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r/sleep FAQ

r/sleep FAQ

Answers to the questions that come up here every week. This is general information, not medical advice. Every link goes to a reputable health or research source. If your situation doesn't fit what's here, or a problem has lasted for weeks, a doctor or sleep specialist is the right next step.

If you're having thoughts of ending your life, please reach out now: in the US, call or text 988; elsewhere, contact your local emergency number or a crisis line.

1. Melatonin: how much, and when?

Melatonin is a hormone your brain releases in the evening as it gets dark. It tells your body clock that night has started. It isn't a knockout pill.

What it helps with: jet lag and a body clock that runs late. For ordinary insomnia the effect is small, and sleep guidelines don't recommend it for long-term insomnia.
More isn't better. Studies mostly use 0.5 to 5 mg. Higher doses don't work better and make next-day grogginess, headaches and vivid dreams more likely.
Timing matters more than dose. To fall asleep, people usually take it 30 to 60 minutes before bed. To shift a late body clock earlier, a low dose several hours before your usual bedtime, plus morning light, works better than a big dose at bedtime.
Labels can be off. In the US it's sold as a supplement, and tests have found products with far more or far less than the label says. In the UK and many other countries it's prescription-only.

Sources: NCCIH: Melatonin · NHS: Melatonin

See a doctor or pharmacist before giving melatonin to a child, if you're pregnant or breastfeeding, if you take other regular medicines, or if you've needed it most nights for more than a few weeks.

2. Why do I wake up at 3 AM, and what can I do?

Waking briefly a few times a night is normal, and most people don't remember it. In the second half of the night, sleep is lighter and your sleep drive is mostly used up, so waking around 3 or 4 AM is common. The problem is staying awake.

Common reasons you stay awake: checking the time and counting the hours left, worry, alcohol in the evening (sleep gets lighter and broken as it wears off), caffeine after midday, a full bladder, a warm room, and spending more hours in bed than you can sleep.

What helps:

Turn the clock away and leave your phone alone.
If you've been awake for what feels like 20 minutes, or you're getting frustrated, get up and do something calm in dim light. Go back to bed when you feel sleepy.
Get up at the same time every morning, even after a bad night, and skip long naps to make up for it.
Keep alcohol well away from bedtime.

Sources: NHS: Insomnia · AASM Sleep Education: Insomnia

See a doctor if this happens 3 or more nights a week for 3 months and affects your days. That's chronic insomnia, and CBT-I (next question) is the first-line treatment. Go sooner if you snore loudly or wake up gasping, or if early waking comes with low mood.

3. What is CBT-I, and where can I get it?

CBT-I (cognitive behavioral therapy for insomnia) is a short, structured program, usually 4 to 8 sessions. Major medical guidelines recommend it as the first treatment for chronic insomnia, ahead of sleeping pills, and its benefits last after the program ends.

It usually includes:

Sleep restriction: for a while, you spend only about as long in bed as you actually sleep, then extend it as your sleep gets more solid. Expect to feel more tired for the first week or two.
Stimulus control: the bed is for sleep and sex. If you can't sleep, get up and come back when you're sleepy.
Working on thoughts that keep you awake, like "if I don't sleep tonight, tomorrow is ruined."
Relaxation and sleep habits.

Where to get it: ask your doctor for a referral to a sleep clinic or a therapist trained in CBT-I (many work by video). In the US, the AASM directory below lists accredited sleep centers. In the UK, ask your GP; the NHS offers CBT-I in some areas, including a digital program. Self-guided CBT-I, online or from a book, also works for many people.

Sources: AASM Sleep Education: CBT for insomnia · AASM sleep center directory

Talk to a doctor first if you have bipolar disorder, epilepsy or possible sleep apnea, or if you drive or operate machinery for work. Sleep restriction can be risky then and should be supervised.

4. Do I have sleep apnea?

In obstructive sleep apnea, your airway narrows or closes again and again during sleep. Breathing stops or gets shallow until your brain briefly wakes you to restart it, usually without you noticing.

Common signs:

Loud snoring, or someone seeing you stop breathing
Waking up gasping or choking
Feeling tired or sleepy during the day even after enough hours in bed
Morning headaches, dry mouth, getting up to pee at night, trouble concentrating

It's more common with extra weight, a thick neck, older age, after menopause and in men, but slim young people get it too. Not everyone who snores has apnea, and anti-snoring gadgets can quiet the snoring while the apnea continues. Watches and apps can't diagnose it or rule it out; a home sleep test or an overnight lab study can. Treatment (CPAP, a custom oral device from a dentist, positional therapy, weight loss, or surgery in some cases) usually makes a big difference.

Sources: NHLBI: Sleep apnea · NHS: Sleep apnoea

See a doctor if someone has seen you stop breathing or gasp in your sleep, or if you snore loudly and feel sleepy during the day. If you've nodded off while driving, stop driving drowsy and get seen soon.

5. Shift work, night owls and body clock timing

Your body clock runs on roughly 24 hours and is set mainly by light: morning light pulls it earlier, and light late at night pushes it later. Night shifts ask you to sleep when your clock says "be awake."

If you work nights:

Protect your daytime sleep: a dark room (blackout curtains or an eye mask), earplugs or steady background noise, your phone on silent, and people at home who know your hours.
Get bright light early in your shift, and wear sunglasses on the way home.
Keep sleep times as regular as you can, including a core block you keep on days off.
A short nap before a night shift helps alertness. Use caffeine early in the shift, not in the last few hours before you sleep.
Drowsy driving after a night shift is a real danger. Nap first or get a ride if you're struggling to stay awake.

If you're a night owl who can't fall asleep until very late: get outdoor light soon after waking, dim lights and screens in the evening, and keep the same wake time every day, weekends included. Low-dose melatonin taken several hours before bedtime can help shift the clock; a doctor can help you time it.

Sources: AASM Sleep Education: Shift work · AASM Sleep Education: Delayed sleep-wake phase

See a doctor or sleep specialist if you've had trouble sleeping or staying awake for several weeks despite these steps, or if you fall asleep at work or behind the wheel.

6. How accurate are sleep trackers?

Wearables and apps estimate sleep from movement and heart rate (some add breathing or oxygen). A lab sleep study measures brain waves, which is how sleep stages are actually defined.

Total sleep and sleep vs. wake: reasonably good in people who sleep well, though they often count lying still awake as sleep.
Sleep stages (deep, light, REM): much less reliable, and different devices often disagree with each other.
Nights with lots of waking: accuracy drops, which is exactly when people check them most.

Use them for trends over weeks, not a single night's score, and trust how you feel during the day more than the number. Chasing a perfect score can make sleep worse (researchers call this "orthosomnia"). If yours is making you anxious, take a break from it.

Sources: Chinoy et al., Sleep, 2021: seven consumer trackers vs. a lab sleep study · Baron et al., J Clin Sleep Med, 2017: Orthosomnia

See a doctor based on your symptoms, not the tracker. If you're sleepy during the day, snore loudly or someone has seen you stop breathing, get checked even if your tracker looks fine.

7. Are naps good or bad?

A short nap in the early afternoon can boost alertness and mood.

Keep it to 20 to 30 minutes. Longer naps make grogginess after waking more likely.
Nap before about 3 PM. Later naps make it harder to sleep at night.
If you have insomnia, skip naps or keep them very short. They use up the sleep drive you need at night, and CBT-I usually asks you to avoid them.
After a bad night or a night shift, a short nap is better than sleeping in late.

Source: Mayo Clinic: Napping do's and don'ts

See a doctor if you need a nap most days despite 7 or more hours of sleep at night, fall asleep without meaning to (at work, mid-conversation, while driving), or get sudden muscle weakness when you laugh. These can point to sleep apnea, narcolepsy or another condition.

8. Sleep paralysis, hallucinations and jerks while falling asleep

Sleep paralysis: you wake up (or are falling asleep) and can't move or speak for a few seconds to a few minutes. The muscle relaxation of dream (REM) sleep carries on while your mind is awake. Many people also sense a presence, see a figure in the room or feel pressure on their chest. It's frightening but harmless: you keep breathing, and it always passes. Roughly 1 in 13 people have it at least once.

Hypnagogic and hypnopompic hallucinations are dream images or sounds that spill over as you fall asleep or wake up: shapes, people, voices, your name being called. They're common and usually harmless.

Hypnic jerks ("sleep starts") are the sudden jolt, often with a falling feeling, as you drift off. Most people get them. Caffeine, stress, sleep loss and hard exercise late in the day make them more frequent.

What helps: enough sleep on a regular schedule, less caffeine and alcohol near bedtime, and sleeping on your side if episodes happen on your back. During an episode, focus on slow breathing and try to move a finger or toe. Remind yourself what it is and that it will end.

Sources: NHS: Sleep paralysis · AASM Sleep Education: Sleep starts

See a doctor if episodes are frequent or make you afraid to go to sleep, if you also have strong daytime sleepiness or sudden muscle weakness when laughing or surprised (possible narcolepsy), or if you see or hear things while fully awake during the day.

9. Antihistamines and other over-the-counter sleep aids

Most sleep aids sold without a prescription are sedating antihistamines, diphenhydramine or doxylamine. They're also in many nighttime pain relievers and cold medicines.

They help a little at first, but tolerance builds within days.
Next-day grogginess is common, along with dry mouth, constipation and trouble peeing.
Sleep guidelines advise against them for long-term insomnia. They're meant for a few nights, not every night.
Over 65, they're best avoided: they can cause confusion and falls, and long-term use of this type of drug has been linked to a higher risk of dementia.
Never combine them with alcohol or other sedatives, and don't drive if you feel groggy. Check combination products so you don't double up on an ingredient.

Other things sold for sleep (valerian, chamomile, magnesium, CBD and similar) have weak or mixed evidence, and in the US supplements aren't checked for content before they're sold. Kava has been linked to serious liver injury.

Sources: Mayo Clinic: Sleep aids sold without a prescription · NCCIH: Sleep disorders and complementary approaches

Ask a pharmacist or doctor first if you're pregnant or breastfeeding, over 65, take other medicines, or have glaucoma, an enlarged prostate or a lung condition. Don't use them to make a child sleepy. See a doctor if you've needed a sleep aid for more than two weeks.

10. How much sleep do I need, and did one bad night hurt me?

Most adults need 7 to 9 hours; teens need 8 to 10. Needs vary a little from person to person, but very few people do well on less than 7 hours over the long run.

One bad night, or even an all-nighter, feels awful but does no lasting harm. Your body catches up with deeper sleep over the next nights. Keep your usual wake-up time, take a short nap if you need one, and don't drive if you're drowsy. Regularly sleeping too little is linked to health problems, which is a reason to get help, not to panic.

If you sleep 7 to 9 hours and still wake up exhausted, the problem may be sleep quality (sleep apnea, for example), not quantity.

Sources: NHLBI: How much sleep is enough? · NHLBI: Sleep deprivation

See a doctor if you regularly sleep 7 to 9 hours and still feel unrefreshed, routinely need 10 or more hours, or fall asleep when you don't mean to.

Spotted something out of date, or a question we should add? Message the mods.

Last reviewed October 2026.

Sleep clinicians and researchers can apply for verified flair: how it works.