How Do Sleeping Pills Affect Your Sleep

Sleep is one of the simplest needs in life, and also one of the easiest to lose. When nights become long and restless, a sleeping pill can look like a simple answer. You take it, your eyes grow heavy, and within a short time you are asleep. For a person who has spent weeks staring at the ceiling, that first quiet night can feel like a gift. The trouble is that the sleep a pill brings is not always the same as the sleep your body makes on its own. It can be lighter, shorter in the deep stages, and full of strange dreams. It can leave you waking in the middle of the night, or waking in the morning feeling as if you never slept at all.

This article explains, in plain words, how sleeping pills affect your sleep: what they do in the brain, why the sleep they produce is often less refreshing, what happens when they are used night after night, and what tends to improve when a person stops relying on them. It is general information only, not individual medical advice. If sleep problems are affecting your health, your work, or your safety, a qualified health professional is the right person to talk to.

What Sleeping Pills Do in the Brain at Night

Most sleeping pills work by calming the activity of the brain. They strengthen the effect of a natural chemical messenger that tells the brain to slow down, and they quiet the signals that keep you alert. In a healthy night, that slowing down happens gradually. Your thoughts loosen, your muscles relax, your breathing steadies, and you drift through light sleep into deeper sleep and then into dreaming sleep, in cycles that repeat through the night. A pill speeds up the first part of that process. It pushes the brain toward sleep before the body has prepared for it in its usual way.

That push is why the pill works so quickly for many people. It is also why the sleep that follows can feel different. The brain has been sedated rather than guided into sleep, and the balance between the stages of sleep can shift. Some pills reduce the amount of deep sleep, which is the stage that helps the body repair itself and helps you wake feeling rested. Others reduce dreaming sleep, which is linked with memory and with processing the events of the day. You may still sleep for seven or eight hours, but if too little of that time was spent in the deeper stages, the night does not refresh you in the way it should.

There is another difference that matters. Natural sleep is not a single unbroken state. You move between stages, you wake briefly and fall back asleep, and your brain keeps a rough sense of the night passing. A pill can flatten that pattern. It can hold you in light sleep for longer, or it can make you so deeply sedated at the start of the night that you miss the normal early cycles, and then leave you in lighter, broken sleep in the second half. Many people describe this as sleeping without resting. They were unconscious for hours, yet their body feels as though it worked all night.

Why Sleep Often Feels Lighter on Sleeping Pills

One of the most common complaints from people who use sleeping pills is that their sleep feels thin. They wake easily at small sounds, they notice the clock more often, and they remember fragments of dreams that feel unusually vivid or strange. This is not imagination. When the drug begins to wear off during the night, the brain can rebound, becoming more active than usual as it tries to catch up on the dreaming sleep it missed earlier. That rebound can bring intense dreams, restlessness, and a sense of being half awake and half asleep at the same time.

Light sleep has a practical cost. A person in light sleep is easier to wake, and once awake, it can be harder to fall back asleep, because the pill that helped at bedtime is no longer at its strongest. Some people then lie awake for an hour or two in the middle of the night, which is exactly the problem they hoped the pill would solve. Others wake early, long before the alarm, and cannot get back to sleep at all. The night has been split into two parts, a heavy first part and a restless second part, and neither part gives the body what it needs.

Over time, the brain can also become used to the pill. The same amount that once brought sleep in twenty minutes may take an hour, or may bring only a shallow, broken sleep. This is tolerance, and it is one of the reasons people increase how often they use the pill, or start to take it earlier in the evening. The pill has not stopped working because the person’s sleep problem has become worse in some new way. It has stopped working as well because the brain has adjusted to its presence, and now expects it in order to fall asleep at all.

Falling Asleep Faster Is Not the Same as Sleeping Well

It is important to separate two ideas that are often confused: falling asleep quickly, and sleeping well. A sleeping pill is often good at the first one and poor at the second. Falling asleep is only the beginning of the night. What matters for how you feel the next day is what happens after that: how much deep sleep you get, how many times you wake, how settled your dreaming is, and whether you wake at a natural point in a sleep cycle or are dragged out of a heavy, drugged sleep by an alarm.

Deep sleep is the stage in which the body does much of its repair work. Muscles relax fully, the heart rate slows, breathing becomes steady, and the brain clears away some of the waste that builds up during the day. If a pill reduces deep sleep, you can sleep for a full night and still wake with aching muscles, a heavy head, and a feeling that your body never fully switched off. This is why some people say they feel more tired after a night on a pill than after a night when they slept badly on their own. The hours were longer, but the quality was lower.

Dreaming sleep matters too. It helps with memory, with learning, and with sorting through feelings from the day. When a pill suppresses dreaming sleep early in the night, the brain often tries to make up for it later, and that catch-up dreaming can be vivid, emotional, and hard to shake off in the morning. People wake from such dreams feeling unsettled, sometimes anxious, sometimes sad, without a clear reason. They may remember the dream in detail, or they may only remember the feeling it left behind. Either way, the night has not done the quiet work it was supposed to do.

Waking in the Night and Waking Too Early

Waking in the middle of the night is one of the most frustrating effects of sleeping pills, because it feels like a betrayal. You did everything right, you took the pill at the right time, you went to bed on time, and still you are awake at three in the morning, watching the ceiling. This happens because most sleeping pills do not last the whole night at the same strength. They peak early, and then their effect fades. As it fades, the brain can wake more easily, and the sleep that remains is lighter and more broken.

Early waking is a related problem. Some people fall asleep easily on a pill, sleep for four or five hours, and then wake before dawn, wide awake and unable to return to sleep. Their body has had some sleep, but not enough, and the rest of the night is lost. The next day is then shaped by that short night: slow thinking, a short temper, and a strong urge to nap in the afternoon, which can make the following night even harder. A pattern begins, in which each poor night makes the next night more difficult, and the pill becomes the only thing the person trusts to break it.

There is also the risk of waking in a confused state during the night. Some people on sleeping pills get up, walk around, eat, or even try to drive, with only a hazy memory of it in the morning. This is not common, but it is a known and serious harm. It happens because the pill can leave a person in a state between sleep and waking, where the body moves but the mind is not fully awake. It is most likely when the pill is taken and the person does not go straight to bed, or when they are woken in the night and try to do something that needs full attention. It is a reminder that a pill that sedates the brain does not switch it off cleanly, and that the hours after taking it need to be treated with care.

The Groggy Morning After

If you have ever taken a sleeping pill and woken feeling as though your head were full of cotton wool, you will know the morning after effect. It is often called a hangover, and it is one of the most widely reported side effects. The drug has not fully cleared from the body by morning, so the brain is still partly sedated when you need it to be alert. Thinking is slow, words come with effort, and simple tasks take longer than they should. Some people describe it as trying to think through fog.

That grogginess is more than an inconvenience. It affects driving, work, and safety. A person who drives to work while still partly sedated may react more slowly to a sudden hazard, may miss a sign, or may drift in attention at exactly the wrong moment. At work, the same slowness shows up as mistakes, forgotten instructions, and a feeling of being a step behind everyone else. For older people, the morning grogginess also raises the risk of falls, because balance and coordination are still dulled when they get out of bed in the dark to use the bathroom.

The length of the grogginess depends on the person, the pill, and how long they slept. A short night makes it worse, because the drug is still strong when the alarm goes off. An older body clears the drug more slowly, so the effect can last longer. Drinking alcohol in the evening makes it worse again, because alcohol also sedates the brain and the two effects add together. Many people try to fight the grogginess with strong coffee, but coffee only masks the feeling of tiredness. It does not restore the sharpness that the drug took away, and by mid-morning, when the coffee wears off, the tiredness can return more strongly.

When Nightly Use Changes Natural Sleep

Using a sleeping pill every night changes the way the brain learns to fall asleep. In a normal night, the brain relies on a set of quiet signals: darkness, a cooler room, a regular bedtime, a body that is tired from the day, and a mind that has wound down. Those signals tell the brain it is safe to let go. When a pill is used every night, the brain begins to rely on the pill instead of those signals. The natural signals grow weaker, because they are no longer needed, and the person starts to believe they cannot sleep without the pill.

This is not a weakness of character. It is how the brain learns. It takes the shortest path to sleep, and if the pill is the shortest path, it will use it. The problem appears when the person tries to stop. The first nights without the pill can be worse than the nights before they ever started, because the brain has forgotten how to fall asleep on its own, and because it is now also dealing with the rebound from the drug wearing off. Sleep may be short, broken, and full of vivid dreams for several nights. Many people take this as proof that they need the pill, and go back to it, and the cycle continues.

Long-term nightly use is also linked with poorer sleep overall, not better sleep. Studies that follow people over months and years find that those who use sleeping pills regularly often report worse sleep quality than those who do not, even though they fall asleep more quickly. Their nights are more broken, their mornings are groggier, and their daytime tiredness is greater. The pill has solved one small part of the problem, getting to sleep, while making the larger problem, sleeping well through the night and waking refreshed, harder to solve.

Sleep, Memory and Thinking the Next Day

Sleep is not a pause in thinking. It is a time when the brain sorts, stores, and strengthens memories. Deep sleep helps move the events of the day into longer-term memory, and dreaming sleep helps link new information with what you already know. When a pill changes the balance of sleep stages, that sorting work can suffer. People often notice it first as small memory slips: forgetting why they walked into a room, losing the thread of a conversation, or struggling to remember a name they know well.

Thinking the next day is affected in other ways too. Attention becomes harder to hold, especially for tasks that need sustained focus, such as reading a long document, following a meeting, or driving a familiar route. Reaction time slows, and the ability to make careful decisions weakens. This is partly the morning grogginess, and partly the poor quality of the night itself. A brain that did not get enough deep sleep is a brain that starts the day already tired, and no amount of willpower fully makes up for that.

For students and for people whose work depends on clear thinking, this cost can be large. They may sleep for eight hours and still feel as though they studied or worked with only half their mind. Over weeks, that gap adds up. It shows in lower performance, in more mistakes, and in a growing sense that thinking itself has become harder. It is easy to blame age, stress, or a busy life for these changes, and all of those can play a part, but the pill, and the poor sleep it produces, is often part of the picture too.

Sleeping Pills, Snoring and Breathing at Night

Sleeping pills relax the muscles of the body, and that includes the muscles that keep the airway open during sleep. When those muscles relax too much, the airway can narrow, and breathing can become noisier and more interrupted. For people who already snore, the snoring often becomes louder on a pill. For people with a condition in which breathing pauses during sleep, the pauses can become longer and more frequent. This is a serious harm, because each pause briefly lowers the oxygen in the blood, and the brain has to wake slightly to restart breathing.

The person may not remember these small wakings, but the body remembers them. The night becomes a series of tiny interruptions, and the sleep is broken even if the person believes they slept through. The next day brings the familiar signs: a dry mouth, a morning headache, a feeling of not having slept, and a strong urge to fall asleep in the afternoon. Over time, the repeated drops in oxygen and the broken sleep put strain on the heart and on blood pressure, and they make the daytime tiredness worse.

This risk is higher for older people, for people who carry extra weight, and for people who drink alcohol in the evening, because alcohol also relaxes the airway muscles. It is also a reason why a pill that helps one person fall asleep can make another person’s nights worse in a way they do not connect with the pill. If snoring has become louder, if a partner has noticed pauses in breathing, or if morning headaches have become common since starting a pill, those are signs worth raising with a health professional, rather than signs to ignore.

What Tends to Improve When the Pills Stop

The first nights after stopping sleeping pills are often the hardest, and it helps to know that in advance. Sleep may be short and broken for a few nights, dreams may be vivid, and the urge to go back to the pill can be strong. This is the rebound, and it is temporary. The brain is relearning how to fall asleep without chemical help, and it is catching up on the deep and dreaming sleep it missed. Most people find that within a week or two, the nights begin to settle, and within a few weeks, sleep starts to feel more natural, even if it is not yet perfect.

As natural sleep returns, the mornings often improve first. The grogginess fades, thinking feels clearer, and the heavy head that used to last until mid-morning lifts earlier in the day. People notice that they can concentrate for longer, that they remember things more easily, and that they feel less irritable in the afternoon. The change is gradual, and it is easy to miss day by day, but over a month it can be large. A person who kept a simple note of how they slept and how they felt in the morning often sees the pattern clearly when they look back.

There is also a quieter improvement that people describe, which is harder to measure but easy to feel. They begin to trust their sleep again. They stop watching the clock with dread, and they stop planning their whole evening around the pill. Bedtime becomes a time to wind down, rather than a time to take a drug and hope it works. That trust does not return in a single night, and it can be shaken by one bad night, but once it is rebuilt, it is a stronger foundation than any pill, because it does not wear off, it does not leave a hangover, and it does not need to be increased to keep working.

Sleeping Pills and the Body Clock

Every person has an inner clock that tells the body when to feel sleepy and when to feel awake. That clock is set mainly by light, by regular mealtimes, and by the time you get up in the morning. It is a slow, steady system, and it works best when the pattern is regular. A sleeping pill does not reset that clock. It overrides it for a night, by forcing the brain into sleep at a time when the clock may not be ready, and then leaving the clock to sort itself out the next day.

When the pill is used night after night, the clock can become confused. The person may feel sleepy at the wrong time in the evening, because the pill is due, rather than because the body is naturally tired. They may feel wide awake long before dawn, because the drug has worn off and the clock has not yet reached the deep part of the night. They may feel groggy in the morning, because the clock is still in night mode while the alarm is demanding a start. Over weeks, the body’s sense of day and night can drift, and the person loses the natural rhythm that once made sleep feel automatic.

This drift is one reason why simply stopping the pill does not always bring good sleep back in a single night. The clock needs time to find its rhythm again, and it needs regular signals to do so: getting up at the same time each morning, even after a poor night, spending time in daylight during the day, eating meals at regular times, and keeping the bedroom dark at night. Those signals are quiet, and they work slowly, but they are the only way to retrain a clock that has been overridden for months. A pill can force sleep, but it cannot teach the clock, and that is a difference worth understanding.

Sleeping Pills and Naps, Caffeine and Late Nights

The way a person spends the day affects the night, and sleeping pills do not remove that link. A long afternoon nap, for example, can take away some of the tiredness the body needs to fall asleep at night, which can make the pill seem less effective, or can make the night more broken. Caffeine late in the day has a similar effect. It keeps the brain alert long after the cup is finished, and it can fight against the pill at bedtime, leaving the person in a strange state of being both sedated and wired at the same time.

Late nights also matter. A person who stays up late watching screens, working, or worrying, and then takes a pill at one in the morning, is asking the pill to do the work that a regular bedtime should have done. The pill may bring sleep, but the sleep will be short, because the morning will arrive too soon, and the body clock will be pushed later again the next night. A pattern begins in which bedtime drifts later, mornings become harder, and the pill becomes the only bridge between a late night and a short sleep.

None of this means that a person who uses sleeping pills is to blame for their poor sleep. Life is busy, work is demanding, and many people have no choice about when they can rest. But it does mean that the pill alone cannot fix a sleep problem that is also shaped by the day. A regular wake time, daylight in the morning, movement during the day, and less caffeine in the afternoon are not cures on their own, yet they give the brain the signals it needs to sleep well, and they make any future night without a pill more likely to succeed.

My Take:

I think the saddest part of the sleeping pill story is that it starts with a reasonable hope. A person is tired, they have tried lying in the dark, they have tried warm milk and early nights, and nothing has worked. A pill that promises sleep feels like kindness, not harm. I understand that hope, and I do not think anyone who takes a sleeping pill is foolish for wanting a good night. The problem is not the hope. The problem is that the pill answers a different question from the one the person asked. They asked for rest. The pill gave them unconsciousness, and those two things are not the same.

I have come to believe that sleep is one of those things that gets worse the harder you chase it. The more you worry about falling asleep, the more awake you become. A pill breaks that worry for one night, but it does not teach the brain how to let go on its own. It teaches the opposite lesson, which is that sleep comes from a tablet, not from the body. That lesson is hard to unlearn, and I think it is the real cost of nightly use, more than any single side effect. A person can recover from a groggy morning. It takes longer to recover from the belief that they cannot sleep without help.

The morning after effect is the part I would most want a new user to understand before they start, because it is the part that affects other people, not just the person who took the pill. A groggy driver is a danger to everyone on the road. A groggy worker can make a mistake that harms a colleague. A groggy parent may be slower to hear a child in the night. We talk about sleeping pills as a private choice, made in a bedroom at night, but their effects do not stay in the bedroom. They follow the person into the car, into the workplace, and into the family home, and I think that wider effect deserves to be part of the decision.

I also think we do not talk enough about the difference between falling asleep and sleeping well. In our busy lives, we measure sleep in hours, as if eight hours of any kind of sleep were enough. It is not. A night of light, broken, dream-filled sleep can leave you more tired than a shorter night of deep, settled sleep. Sleeping pills often give you the hours and take away the depth, and then you wake and wonder why the hours did not help. I would rather have fewer hours of real sleep than a full night of shallow sleep, and I think most people would agree once they have felt the difference for themselves.

What gives me hope in this subject is how often natural sleep returns when it is given a fair chance. The brain wants to sleep. It has done so for your whole life, long before any pill existed, and it has not forgotten how. It needs regular hours, a dark and cool room, a body that has moved during the day, and a mind that has had time to wind down. Those things sound simple, and they are simple, but they are not easy when life is busy and stressful. Still, they work more slowly and more honestly than a pill, and their effect does not fade with time. A good sleep routine, built patiently over weeks, is a better investment than a prescription that needs to be renewed.

I think about older people and sleeping pills with particular care, because they are the ones most often given these pills, and the ones most harmed by them. An older body clears the drug more slowly, balance is already less steady, and a fall in the night can break a hip and change a life. A pill that helps a younger person fall asleep can leave an older person confused, unsteady, and at risk in the dark. If an older person in your family is using a sleeping pill every night, I would ask you to talk with them, gently, about whether the pill is still helping, and whether a health professional could review it. That conversation may be uncomfortable, but it is worth having.

There is a question I hear often, which is whether it is too late to stop after years of nightly use. I do not believe it is ever too late. The first week may be hard, and the nights may be broken, but the brain is remarkably good at relearning. People who have used sleeping pills for years often say that the hardest part was not the poor sleep after stopping, but the fear of the poor sleep before stopping. Once they got through the first difficult nights, they found that their sleep, while not perfect, was more their own, and that the mornings were clearer. That sense of ownership, of sleeping because your body chose to sleep, is something a pill can never give you.

I would also say something to anyone who is lying awake tonight, wondering whether to take a pill. I understand the temptation, and I am not here to judge you for it. But I would ask you to think about what tomorrow needs from you. If you need to drive, to work, to look after children, or to make careful decisions, a groggy morning may cost you more than a short night. Sometimes the honest choice is to accept a poor night, get up, have a quiet day, and let the body’s natural tiredness do its work the following night. It is not a pleasant choice, but it is an honest one, and honesty about sleep, like honesty about anything else, tends to pay off in the long run.

Money is a smaller part of this story, but it still matters. Sleeping pills cost money every month, and that money adds up over a year. A person who stops using them not only sleeps more naturally, they also keep that money for food, for their family, or for something that brings them joy. It is a small freedom, but small freedoms add up, and they are a reminder that the pill was not free. It cost money, it cost morning clarity, and it cost trust in your own body. When you add those costs together, the price of a good night’s sleep turns out to be higher than it first looked.

Children are another reason I take this subject seriously. A parent who is groggy in the morning is a parent who is slower to respond, less patient, and less present. Children notice that, even when they cannot name it. They notice when a parent is half asleep at breakfast, or when they forget a promise made the day before. I do not say this to add guilt. I say it because many parents tell me that their children were the reason they finally decided to change. They wanted to be fully awake for the people who needed them most, and that wish was stronger than the fear of a bad night.

I think the most useful thing anyone can do for their sleep is to protect the hour before bed. That hour is when the brain decides whether it is safe to let go. If that hour is filled with bright screens, bad news, arguments, and worry, the brain will stay alert. If that hour is quiet, dim, and calm, the brain will begin to slow down on its own. A pill tries to force that slowing down, but a calm hour invites it, and an invitation lasts longer than a force. I know that a calm hour is hard to find in a busy household, but even twenty quiet minutes, without a phone, can make a difference.

Finally, I want to be clear about what I am not saying. I am not saying that no one should ever use a sleeping pill. There are times when a short course, under a health professional’s guidance, can help a person through a difficult period, such as after a bereavement or during a short crisis. What I am saying is that nightly use over months and years is a different matter, and that it deserves an honest look at what it gives and what it takes. If you are using a pill every night, talk to a health professional about your sleep, about your mornings, and about whether there is a safer way forward. That conversation is not a sign of failure. It is a sign that you are taking your sleep, and your health, seriously.

I think we should also be honest about how lonely poor sleep can feel. Lying awake while the rest of the house is quiet, and the rest of the world seems to be sleeping soundly, can make a person feel alone in a way that is hard to describe to someone who sleeps well. A pill can feel like company in that loneliness, a small act that says you are doing something about the problem. I understand that feeling, and I do not want to take it away without offering something in its place. What I would offer is the knowledge that many people have been in that same dark room, and that many of them found their way back to natural sleep, slowly, with help, and without shame.

There is a patience in this subject that I think is worth naming. Natural sleep does not return because you demand it, or because you have read the right article. It returns because you give it the conditions it needs, night after night, and because you forgive the bad nights instead of punishing yourself for them. A bad night is not a failure. It is a night, and the next night is a new chance. That way of thinking is gentler than the pill’s promise, and it is also more honest, because it does not pretend that one tablet can fix a pattern that took months to build.

I also think about the simple pleasure of waking up rested, and how easy it is to forget what that feels like when every morning has been groggy for years. A rested morning is not dramatic. You open your eyes, your head is clear, your body feels light, and the day ahead seems possible rather than heavy. That feeling is worth working towards, and it is worth a few difficult nights to reach. When it returns, even once, it is a reminder of what sleep is supposed to do, and it makes the effort of the weeks before feel worthwhile.

If you are a partner, a parent, or a friend of someone who uses sleeping pills every night, I would ask you to be patient with them, and also honest with them. They may be defensive about the pill, because it feels like the only thing keeping them going. They may also be frightened of the nights without it. Listening without judgement, and offering to help with a regular routine, a quiet evening, or a visit to a health professional together, can do more good than any lecture. Change is easier when a person does not feel alone in it.

One last thought stays with me, and it is this: sleep is not a luxury, and it is not a reward for a good day. It is a basic need, like food and water, and when it is broken, everything else in life becomes harder. A pill that promises to fix it deserves to be judged by whether it truly restores rest, not only by whether it brings unconsciousness. If it does not restore rest, then it is time to look for a better answer, with help, with patience, and with the belief that your body still knows how to sleep, even if it has forgotten for a while.

I also think about the simple act of getting up in the morning, and how much it changes when sleep has been real. You do not need an alarm to drag you out of a heavy fog. You open your eyes, you stretch, you feel ready to face the day, even if the day will be hard. That readiness is not a small thing. It shapes how you speak to your family, how you work, and how you handle the first problem that arrives. A pill that leaves you groggy takes that readiness away, and it does so quietly, day after day, until you forget what a clear morning felt like.

Frequently Asked Questions

What are the main side effects of sleeping pills on sleep?

The main side effects on sleep are lighter and more broken sleep, less deep sleep, vivid or strange dreams, waking in the middle of the night, waking too early, and waking in the morning feeling unrefreshed. Some people also feel groggy, slow, and unsteady the next morning, and over time nightly use can make natural sleep harder to achieve without the pill.

How quickly can sleeping pills affect sleep?

Some effects appear on the first night, such as falling asleep faster, feeling groggy in the morning, and having vivid dreams. Other effects build up over weeks or months, such as lighter sleep, waking in the night, tolerance to the pill, and a growing reliance on it to fall asleep at all.

Can the harm sleeping pills causes to sleep be reversed?

Much of the harm can improve after use stops, especially the morning grogginess and the lighter, broken sleep, as the brain relearns how to fall asleep naturally. The first nights after stopping can be worse, with short sleep and vivid dreams, but for most people sleep settles over one to a few weeks. Lasting changes are more likely after long or heavy use, and a health professional can give advice for one person.

Why does sleeping pills affect sleep?

Sleeping pills affect sleep because they calm the brain by strengthening its natural sleep signals, which changes the balance between light sleep, deep sleep, and dreaming sleep. That shift can reduce deep sleep, disturb dreaming sleep, and leave the brain more likely to wake in the second half of the night as the drug wears off.

When should someone seek help about sleeping pills and sleep?

Seek help if sleep stays poor night after night, if you feel groggy or unsteady in the morning, if you wake in the night confused or cannot remember what you did, if snoring has become louder or breathing pauses have been noticed, or if you feel you cannot sleep without the pill. A health professional can review the situation and suggest safer options.

Where can I learn more about sleeping pills?

Trusted sources include the National Institute on Drug Abuse, the NHS, the World Health Organization, and the Centers for Disease Control and Prevention. Their links are in the Sources section below.

Sources

This article is general information only. It is not individual medical advice. If you are worried about your health, talk to a qualified health professional.