Is It Bad to Sleep in on Weekends

General information only: this article explains whether sleeping in at the weekend is harmful, and when a lie-in starts to cause problems. It is general information, not personal advice. If sleep problems or daytime tiredness keep happening, a qualified health professional is the right person to ask.

Saturday morning, no alarm, and the house is quiet. Is it bad to stay in bed? For most people, the short answer is no. Sleeping in at the weekend is not bad on its own. It is a normal, human response to a busy week, and an extra hour or two in bed can do real good. The problem starts when the lie-in grows very long, when wake-up times swing by three or four hours between weekdays and weekends, and when Monday morning begins to feel like travelling to another time zone. This article explains where the line is, why a long lie-in can upset the week, and how to enjoy a slow weekend morning without paying for it on Monday.

What Sleeping In Really Means

Sleeping in means waking later than usual. For a person who wakes at six during the week, sleeping in might mean waking at seven or eight on Saturday. For a student who wakes at seven for school, it might mean waking at nine. For a night-shift worker, it might mean something else entirely. The word itself does not tell you whether the lie-in is good or bad. What matters is how much later you wake, how often it happens, and how you feel afterwards.

It helps to separate two different kinds of sleeping in. The first is a short lie-in after a short week: you slept six hours a night from Monday to Friday, and on Saturday you sleep eight hours. That lie-in is the body taking the rest it missed, and it usually leaves you feeling better. The second is a very long lie-in: you slept six hours a night during the week, and on Saturday you sleep until noon, taking in eleven or twelve hours in total. That lie-in gives the body more hours, but it also moves the whole day later — breakfast becomes lunch, lunch becomes a late snack, and the evening stretches far into the night. The extra hours are real, but so is the shift, and the shift is what causes trouble.

Age changes the picture too. A teenager’s body clock naturally runs later than an adult’s, so a teenager who sleeps until nine or ten at the weekend may simply be following their own clock. A young child, on the other hand, often wakes early even at the weekend, because their clock runs earlier. An older person may wake at five or six no matter what day it is. None of these patterns is wrong on its own. Sleeping in is only a problem when it leaves the person feeling worse, not better — groggy, headachy, out of step with the day, or unable to fall asleep at a normal time that night.

It is also worth saying that sleeping in is not the same as being lazy. Laziness is a judgement about character, and it is usually unfair. A person who sleeps in after a week of early starts, long days, and broken nights is not lazy. They are tired, and their body is asking for rest. The question to ask is not, “Am I lazy?” but, “Did this lie-in help me, or did it make the next day harder?” If it helped, it was a good lie-in. If it made Monday harder, it was too long, and a shorter lie-in next time will probably work better.

Why a Long Lie-In Can Feel Strange

Anyone who has slept until noon knows the strange feeling that follows. Instead of waking up fresh, you wake up groggy, with a dry mouth, a dull headache, and a sense that the day has already passed you by. The room is bright, the house is already busy, and you feel a step behind everyone else. This heavy feeling has a name — sleep inertia — and it happens when you wake up from a deep stage of sleep, or when you wake up far from your usual time. The brain needs time to switch from sleep mode to waking mode, and a very long sleep can make that switch slower, not faster.

Part of the strangeness comes from missing the morning. Morning light is the strongest signal the body uses to set its daily clock. When you sleep through the morning, you miss that light, and the body clock stays in its night-time setting for longer. A late breakfast also shifts the body’s sense of time, because meals are another signal the clock uses. When light and meals both arrive hours late, the body thinks the day started later than it did, and it prepares for sleep later that night as well. That is why a long Saturday lie-in often leads to a late Saturday night, which leads to another long lie-in on Sunday, and the whole weekend drifts later and later.

Mood can change after a very long lie-in too. Some people feel low or flat, as if they have wasted the day, even though they were simply resting. Others feel irritable, because the house is already noisy, the plans for the day have changed, and the quiet morning they wanted has gone. These feelings are not a sign that sleep itself is bad. They are a sign that the day has lost its shape. A morning with light, breakfast, and a short walk gives the day a beginning. A morning that starts at noon has no beginning, and the rest of the day can feel shapeless and unsatisfying, even if the body is rested.

There is also a simple, practical cost: a very long lie-in eats the weekend. Saturday is often the only full day for family, for rest, for shopping, for a walk, or for time outside. Sleeping until noon takes away the best hours of that day — the cool, quiet morning hours when the light is gentle and the streets are calm. Many people find that they enjoy the weekend more when they wake a little earlier and use the morning, even if they are still a little tired. The rest they get from a shorter lie-in, plus a morning walk and a proper breakfast, often leaves them feeling better than a very long sleep that swallows the whole morning.

The Body Clock and the Monday Morning Crash

The body keeps time with a quiet internal clock, a small system in the brain that controls when you feel sleepy and when you feel awake, when your temperature rises and falls, and when your body releases the hormones that manage hunger and energy. This clock runs on a roughly twenty-four-hour cycle, and it is set each day by light, by meals, and by regular sleep and wake times. When those times stay steady, the clock runs smoothly. When they swing widely between weekdays and weekends, the clock gets confused, and Monday is when the confusion shows up most clearly.

The Monday crash after a long weekend lie-in is familiar to millions of people. The alarm rings at six, but the body thinks it is still two in the morning. The eyes will not open, the head feels thick, and the first hour of the day feels like wading through deep water. At school, the first lesson feels impossible. At work, the first meeting feels like it is happening in another language. This is often called social jet lag, because the feeling is very much like the jet lag a traveller feels after crossing time zones. The person never left home, but their body clock travelled several hours over the weekend and now has to travel back.

The size of the gap decides how bad Monday feels. A gap of one hour — waking at seven instead of six — is barely felt. The body adjusts within a few hours, and by lunchtime Monday feels normal. A gap of two hours is noticeable in the morning, but most people recover by the afternoon. A gap of three or four hours, which is common when a person wakes at six during the week and ten or eleven at the weekend, can make the whole of Monday feel heavy, and it can take until Tuesday for the clock to settle fully. The lesson is not that lie-ins are bad, but that large swings are costly. A small swing gives most of the rest with little of the Monday price.

Light is the fastest way to help the clock move back. Stepping outside into daylight on Monday morning, even for ten minutes, tells the clock that the day has begun. Eating breakfast at the usual time helps too, as does keeping the evening calm and going to bed at the usual time on Sunday night. These small steps do not remove the Monday feeling entirely, but they shorten it. The worst thing to do on Monday is to stay in dim light, skip breakfast, and drink coffee all morning while sitting still. That keeps the clock in its weekend setting for longer, and the fog lasts well into the afternoon.

Morning Light, Breakfast and the Rest of the Day

A weekend lie-in does not only change sleep. It changes the whole shape of the day, and the shape of the day matters as much as the hours in bed. When you wake late, breakfast is late or skipped, lunch is pushed later, and dinner may be eaten close to bedtime. The body, which expects food at regular times, has to adjust to a new pattern for two days, and then adjust back again on Monday. That constant adjusting is tiring in itself, and it can leave the stomach feeling unsettled, the appetite confused, and energy levels uneven through the day.

Morning light is the other piece that gets lost. Daylight in the morning is the strongest signal for the body clock, stronger than any alarm or cup of coffee. It tells the brain to stop making the sleep hormone, to raise the temperature, and to get ready for the day. A person who sleeps through the morning misses that signal, and the clock drifts later. A person who wakes at a reasonable time, opens the curtains, and steps outside for a few minutes gets the signal clearly, and the whole day feels steadier. This is true even on a cloudy day. Outdoor light, even on a grey morning, is far brighter than indoor light, and it works on the clock in a way that a lamp cannot.

Movement fits into the same picture. A short walk in the morning, even ten minutes around the block, wakes the body gently and helps the clock stay on track. A weekend spent entirely in bed and then on the sofa, with little movement and little light, can leave a person feeling more tired, not less, even after many hours of sleep. The body needs movement to feel awake, just as it needs sleep to feel rested. A lie-in followed by a walk and a proper breakfast is a very different day from a lie-in followed by hours indoors in dim light, and most people can feel the difference by the afternoon.

None of this means you should give up slow weekend mornings. A slow morning — waking a little later, eating breakfast without rushing, sitting with a cup of tea — is one of the pleasures of the weekend, and it is good for the mood. The point is to keep the slowness within a shape: wake within an hour or two of the usual time, get some daylight, eat at a roughly normal time, and move a little. That shape gives you the rest of the lie-in and the steadiness of a normal day, and it leaves Monday feeling like a normal day too.

When a Lie-In Is Harmless — and When It Is Too Much

A lie-in is harmless when it is modest, occasional, and leaves you feeling better. An extra hour after a busy week, a slow morning after a late night, a longer sleep after a night shift — all of these are normal and healthy. The body is taking what it needs, and the next day feels clearer. There is no rule that says you must wake at the same minute every day of your life. Life is not that neat, and a little flexibility is part of good sleep, not a failure of it.

A lie-in becomes too much when it is very long, very often, and leaves you feeling worse. Sleeping until noon every weekend, waking with a headache, feeling groggy for hours, and then struggling to fall asleep on Sunday night are signs that the lie-in has gone past the point of help. The same is true if Monday always feels like a crash, if you need several cups of coffee to get through the morning, or if you feel sleepy all week despite long weekend sleeps. These are signs that the gap between weekday and weekend times is too wide, and that the week itself, not just the weekend, needs attention.

There is also a difference between sleeping in because you are tired and sleeping in because you cannot get out of bed. Most lie-ins are the first kind: the body is tired, and it takes the rest it needs. But if a person regularly sleeps ten or twelve hours and still feels exhausted, or if they feel low, lose interest in things they used to enjoy, or struggle to get up even after a long night, it may be a sign of something else — low mood, a health problem that affects sleep, or a sleep disorder such as sleep apnoea, where breathing stops and starts during the night. This article cannot say which it is for any one person, but it can say that constant, heavy tiredness is worth talking about with a health professional, not just sleeping through.

The practical line is simple to remember: one or two extra hours is usually fine, three or four extra hours is often too much, and the test is how you feel on Monday and Tuesday. If you feel clear and steady by Tuesday, the lie-in did its job. If you still feel out of step by Wednesday, the pattern needs to change. You do not need a perfect schedule. You need a gap small enough that the body can cross it without a crash.

Children, Teenagers and Older People

Sleeping in looks different at different ages, and what is fine for one age can be a problem for another. Young children usually wake early, even at weekends, because their body clocks run early and their sleep is deep and regular. A young child who sleeps in very late at the weekend may simply be catching up after a busy week, or may have gone to bed too late the night before. For children, the most helpful thing is a regular bedtime and wake-up time, even at weekends, within an hour or so. A child who sleeps until noon on Sunday and then cannot fall asleep on Sunday night will struggle at school on Monday, and the whole week can start badly.

Teenagers are the group most often blamed for sleeping in, and the blame is usually unfair. A teenager’s body clock naturally shifts later during the teenage years, so they feel sleepy later at night and wake later in the morning. A teenager who sleeps until ten at the weekend is often following their own clock, not being lazy. School start times, which are early, cut their sleep short all week, so the weekend lie-in is the body taking back what the week took away. A modest lie-in is healthy for a teenager. What helps most is keeping the gap small — waking within two hours of the school-day time — and getting morning light and breakfast, so Monday is not a shock. Blaming a teenager for sleeping in rarely helps. Helping them keep a steadier pattern usually does.

Older people often have the opposite pattern. They may wake early, even at weekends, and find they cannot sleep in even if they try. Their sleep is lighter, they may wake during the night, and they may feel sleepy in the afternoon. For an older person, a lie-in is not usually the issue. A short nap in the afternoon, or an earlier bedtime, is often more helpful than trying to sleep late in the morning. If an older person suddenly starts sleeping very long hours, or feels very drowsy during the day, it is worth talking to a doctor, because a change in sleep can be a sign that something else needs attention.

For parents, the practical point is to keep the household pattern steady without making it a battle. A regular breakfast time, some morning light, and a calm evening help every age, and they cost nothing. Children copy what they see, so a parent who keeps a fairly steady wake-up time, even at weekends, sets a pattern the whole family can follow. That does not mean no lie-ins at all. It means lie-ins that are modest, enjoyable, and followed by a normal day, rather than lie-ins that swallow the morning and leave Monday in pieces.

A Gentler Weekend Wake-Up That Still Feels Like a Rest

It is possible to have a restful weekend without sleeping until noon, and many people find they enjoy the weekend more when they do. The gentler pattern is simple: sleep an extra hour, not four; wake up slowly, without an alarm if you can; open the curtains and let the light in; eat breakfast at a roughly normal time; and take a short walk outside. The morning still feels slow and restful, because there is no rush, no bus, no meeting. But the day has a beginning, and by lunchtime you feel awake, clear, and ready to enjoy the rest of the weekend.

Sunday night deserves special care, because it sets up Monday. Go to bed at the usual weekday time, or close to it, even if you do not feel tired yet. Keep the last hour before bed calm: less bright light, less scrolling on a phone, a quiet room. A person who goes to bed at the usual time on Sunday, after a modest lie-in that morning, will usually fall asleep without trouble and wake on Monday feeling almost normal. A person who stays up late on Sunday, after sleeping until noon, will often lie awake, wake up tired, and start the week already behind. The Sunday night bedtime is the single most useful habit for a good Monday.

It also helps to plan something pleasant for Monday morning, if you can. A favourite breakfast, a short walk before work, a moment of quiet before the day begins — these small things give Monday a gentler start, and they make the early alarm feel less harsh. The Monday crash is partly about the clock, but it is also about the feeling that the weekend is over and the week is a burden. A small pleasure on Monday morning does not fix the clock, but it softens the landing, and a softer landing makes the whole day easier.

In the end, sleeping in at the weekend is not bad. It is a normal, healthy way to rest after a busy week, as long as it stays within reason. An extra hour or two is a gift to a tired body. A very long lie-in, repeated every weekend, is a gift that comes with a Monday price, and the price is paid in foggy mornings, slow thinking, and a body clock that takes days to settle. Keep the lie-in modest, keep the light and the meals roughly on time, and keep Sunday night steady, and the weekend will do what it is meant to do: rest you, without stealing Monday from you.

My Take:

If you ask me whether it is bad to sleep in on weekends, my answer is no — not in itself, and not if you keep it modest. I enjoy a slow Saturday morning as much as anyone, and I think it is one of the small pleasures that makes the weekend feel like a weekend. There is no alarm, no rush, no bus to catch. You wake when your body is ready, you eat breakfast slowly, and the day begins in its own time. That is rest, and rest is good. What I do not enjoy, and what I think causes the trouble, is the very long lie-in that swallows the whole morning, leaves you groggy until lunch, and then makes Monday feel like a punishment. The difference between those two mornings is not laziness. It is simply how far the clock moved.

I think we judge sleeping in too harshly. In many homes, a person asleep at ten on Saturday is called lazy, while a person awake at six, tired and grumpy, is called hardworking. I do not think that is fair. The tired person at six may be running on very little sleep, and the person asleep at ten may be taking the rest their body was denied all week. I would rather judge a lie-in by how it leaves you feeling than by the time on the clock. If you wake feeling clearer and kinder, it was a good lie-in. If you wake feeling groggy and out of step, and Monday feels like a crash, it was too long. That is a kinder and more honest test than any rule about waking times.

I also think the Monday problem is real, and it is worth taking seriously. I have felt it myself: a weekend of late mornings, a Sunday night that stretches too far, and then a Monday alarm that feels like it is ringing in the middle of the night. The whole day feels slow, and by the afternoon I am wondering why I feel so tired when I slept so much. The answer, I have learned, is that I slept at the wrong times, not too little. My body clock had moved, and it needed a day or two to move back. Once I understood that, I changed the way I use the weekend. I still sleep in, but only by an hour or two, and I go to bed at a normal time on Sunday. Monday is not perfect, but it is a normal day, and a normal Monday is worth more than a long lie-in.

There is something I want to say about teenagers, because they are the ones most often shamed for sleeping in. I think that shame is misplaced. A teenager’s body clock runs later than an adult’s, and school starts early, so the week cuts their sleep short night after night. When they sleep until ten on Saturday, they are not being lazy. They are taking the sleep their body needs, and their body is doing exactly what it should do. I would keep the lie-in modest, and I would help them get light and breakfast in the morning, but I would not call them lazy for it. Kindness works better than blame, and a teenager who feels understood is more likely to keep a steady pattern than one who feels judged.

I think about parents here too, because a parent’s weekend is rarely their own. A parent who sleeps in on Saturday may be woken by a child at seven anyway, or may use the morning to do the washing, the shopping, and the cooking that the week left undone. For a parent, a lie-in is often a dream rather than a habit, and when it happens, it should be enjoyed without guilt. My view is simple: if you get the chance to sleep an extra hour, take it, and do not apologise for it. The house will wait, the washing will wait, and you will be a kinder, calmer parent for the rest of the day because you rested.

I also want to be honest about the people for whom a lie-in is not a choice but a sign. If you sleep ten or twelve hours every weekend and still feel exhausted, or if you cannot get out of bed even after a long night, that is not a normal lie-in. That is tiredness that needs attention, and I think it is worth talking to a doctor about it, rather than sleeping longer and longer and hoping it passes. It could be that your weekday sleep is far too short, or that your sleep is broken by snoring or worry, or that something else in your health needs care. A lie-in can ease tiredness, but it cannot fix a health problem, and asking for help is not a weakness. It is the sensible thing to do.

If I had to give one piece of advice about weekend lie-ins, it would be this: keep the gap small. Sleep an extra hour, enjoy a slow breakfast, take a walk in the daylight, and go to bed at your usual time on Sunday night. That is not a strict rule, and it is not a punishment. It is a gentle shape for the weekend that gives you rest without stealing Monday. I have tried the long lie-in, and I have tried the gentle one, and the gentle one leaves me feeling better by Tuesday, while the long one leaves me feeling out of step until Wednesday. I would rather have a weekend that ends well than a Saturday morning that feels wonderful for an hour and costs me two days.

In the end, my view is simple and hopeful: sleeping in is not bad. It is a normal part of resting, and it becomes a problem only when it goes too far, too often. Enjoy the slow morning, take the extra hour, and then let the day begin. Get some light, eat at a normal time, move a little, and protect Sunday night. Do that, and the weekend will rest you, Monday will feel like a normal day, and the week will start clean. That is what a weekend is for, in my view — not to escape the week, but to return to it rested, steady, and ready.

I think about the shape of a good Saturday, and it is not a shape I learned from a book. It is a shape I learned from watching ordinary families. The house wakes slowly, someone makes breakfast, the curtains are opened, and the day begins without a rush. There is time for a walk, time for a conversation, time to sit in the light. Nobody is checking the clock every five minutes, but nobody is asleep at noon either. That middle ground — restful, but not lost — is what I think a weekend morning should feel like. It is rest with a beginning, and a beginning is what makes the rest of the day feel good.

I also think we should be careful about the language we use around sleep. Words like lazy, wasteful, and undisciplined are often aimed at people who sleep in, and they do real harm. A person who hears those words often enough starts to believe them, and then feels guilty every time they rest, even when rest is exactly what they need. I would rather use different words: tired, rested, steady, out of step. Those words describe what is actually happening, without judging the person. A tired person who sleeps in is not lazy. They are tired. A rested person who wakes late is not undisciplined. They are rested. If we used honest words, I think many people would sleep better and feel kinder towards themselves.

Another thought I keep coming back to is the value of a regular breakfast. It sounds like a small thing, but breakfast is one of the signals the body clock uses to know that the day has begun. A person who sleeps until noon and then eats their first meal at one o’clock has told their body that the day started at one, and the body will prepare for sleep much later that night. A person who wakes at eight, eats breakfast at nine, and then enjoys the day has told their body that the day started at eight, and the body will be ready for sleep at a normal time. I do not think breakfast needs to be fancy. Bread, eggs, fruit, tea — whatever is normal in your home is enough. What matters is that it happens at a roughly normal time, so the clock has something to hold on to.

I also want to say something about the people who cannot sleep in at all, even when they want to. A parent with a small child, a worker with an early shift, a person who wakes at five no matter what — these people often look at a lie-in as a luxury they will never have. My view is that they do not need a lie-in to rest well. A quiet evening, an earlier bedtime, a short nap in the afternoon, or even twenty minutes of sitting in daylight with a cup of tea can do a great deal. Rest is not only about sleeping late. It is about giving the body a pause, in whatever form the day allows, and a pause taken kindly is worth more than a lie-in taken with guilt.

Finally, I want to leave you with a simple test for your own weekends. After your lie-in, ask yourself three questions: Did I wake feeling clearer, or groggier? Did I enjoy the rest of the day, or did it feel shapeless? Did Monday feel like a normal day, or like a crash? If the answers are clearer, enjoyed, and normal, your lie-in is working, and you should keep it exactly as it is. If the answers are groggier, shapeless, and crash, the lie-in is too long, and a shorter one will probably serve you better. You do not need anyone else to tell you the answer. Your own body, your own day, and your own Monday will tell you, clearly and honestly, if you listen to them.

I also think it helps to remember that the weekend is for the whole household, not just for one person. A lie-in that leaves one person rested but the rest of the family waiting, hungry, and unsure what the day holds is not really a restful morning for anyone. A better pattern is one the whole family can share: a slightly later wake-up, a breakfast together, and then a day that everyone can enjoy. Children feel safer when the day has a shape, partners feel happier when plans are clear, and the person who slept in feels better when they wake to a calm house rather than a house already in a rush. Rest is at its best when it is shared, not when it is taken alone while everyone else waits.

One more honest thought: a lie-in cannot fix a week that is always too busy. If every weekday is a rush from early morning to late night, with no time to breathe, then a Saturday lie-in is only a pause, not a cure. The week itself needs a little more room — an earlier finish, a shorter evening of screens, a bedtime that is protected like an appointment. I know that is not always easy, and I would not pretend it is. But I do believe that a small change in the week, kept for a month, can change the whole feeling of the weekend. When the week leaves a little more room for sleep, the weekend lie-in becomes a pleasure rather than a rescue, and Monday becomes a normal day rather than a crash. That is the weekend I would wish for everyone.

I also think the fairest way to settle the question for yourself is a small two-weekend test, because advice means little until you have felt the difference in your own body. One weekend, sleep in as long as you like, right up to noon if that is what you want, and notice how Monday feels. The next weekend, wake just an hour or two later than usual, open the curtains, eat breakfast at a normal time, and take a short walk before lunch. Then compare the two Mondays honestly. Which morning felt clearer? Which afternoon had more energy? Which Sunday night let you fall asleep more easily? I have done this myself, and the answer was plain: the modest weekend left me brighter on Monday, while the very long one left me foggy until Tuesday. Your answer might be the same, or it might be different, and that is fine. The test is yours, and whatever it shows you is the right answer for your own life, better than any rule I could give you.

Frequently Asked Questions

What do people notice first when they ask “is it bad to sleep in on weekends”?

People usually notice how they feel after the lie-in — whether they wake up fresh and clear, or groggy, headachy, and out of step with the day. They may also notice that Monday morning feels harder after a very long weekend sleep, which is often the first sign that the lie-in was too long.

How is “is it bad to sleep in on weekends” different from one day to the next?

It differs with the size of the lie-in, the week before it, and the person’s age. A one-hour lie-in after a busy week feels easy, while a four-hour lie-in after a short week can leave Monday feeling like jet lag. A Saturday lie-in and a Sunday lie-in can also feel different, because Sunday sets up Monday.

Can “is it bad to sleep in on weekends” feel different for children and adults?

Yes, it can feel different. Teenagers naturally sleep later, so a weekend lie-in often suits their body clock, though a very late wake-up still makes Monday hard. Young children usually wake early anyway, and older people often wake early too, so a long lie-in is less common for them and may feel strange when it happens.

What makes “is it bad to sleep in on weekends” easier to understand in plain words?

It becomes easier when you think of the body as a clock, not a bank. A bank lets you pay back hours in one go, but a clock does not like to be moved by several hours and then moved back again. A small move is easy to correct, while a big move takes days to settle, and Monday shows the cost.

In simple words, what does “is it bad to sleep in on weekends” mean?

In simple words, it means asking whether waking late at the weekend harms your sleep or your week. A modest lie-in of an hour or two is usually fine and can help you feel rested, but a very long lie-in can shift your body clock, make Monday hard, and make it harder to fall asleep on Sunday night.

Why do people ask “is it bad to sleep in on weekends” so often?

People ask it often because almost everyone sleeps in at the weekend, and almost everyone has felt the Monday crash that sometimes follows. They enjoy the slow morning, but they wonder whether it is the reason Monday feels so hard, and they want a clear answer they can use without giving up the pleasure of a lie-in.

Sources

• NHS — general health information: https://www.nhs.uk/
• World Health Organization — health topics: https://www.who.int/
• Centers for Disease Control and Prevention — health information: https://www.cdc.gov/
• Mayo Clinic — general health information: https://www.mayoclinic.org/
• Healthline — general health information: https://www.healthline.com/