How much sleep do you need?
Each person's sleep needs vary, but on average, most people need 6 to 9 hours of sleep per night. If you feel refreshed after a night's sleep and don't feel tired during the day, you're probably getting enough. Keep reading to find out the signs that you're not getting enough sleep.

How long should it take to fall asleep?
Most people fall asleep within 10 to 20 minutes. If you're having trouble falling asleep, don't lie in bed awake. Get out of bed and read or watch TV until you feel drowsy again. Staying in bed may make you more anxious about not being able to fall asleep and reduces the association your brain has between being in bed and being asleep. If you consistently have trouble falling asleep, read "Tips for good sleep hygiene" and talk to your doctor.

Is it okay to nap during the day?
For babies and toddlers, napping during the day is needed, but most adults don't need to nap. Short naps of 10 to 30 minutes are usually okay if you're not having any trouble falling or staying asleep at night. If you do have trouble sleeping, then try to avoid napping during the day. Check out "Why should I take a nap?" for more insight into the benefits and essentials of a good nap.

When I try to go to bed earlier, why can't I fall asleep?
You might have good intentions when you go to bed early, but if you go to bed a lot earlier than usual, you may have trouble falling asleep. Why? Your body has a built-in clock that influences when you are ready to sleep. This built-in clock is called your circadian rhythm and it approximates a 24-hour cycle. If you want to start to go to bed earlier, gradually change your sleep-wake cycle by going to bed a little earlier than normal each night. Learn more about circadian rhythm sleep disorders.

What causes dreams?
This is a question that has eluded experts for decades, and they still aren't exactly sure how dreams come about. They do know that what you experience during the day can affect the content of your dreams. Dreams can also be influenced by emotional experiences. Not everyone remembers their dreams, and the most vivid dreams occur during REM (rapid eye movement) sleep. Read "Dreams: The Mysteries of Sleep" for more information about this fascinating topic.

I can't fall asleep because I feel like I have to move my legs around. What could this be?
You might have a condition called restless legs syndrome (RLS). People with this syndrome have uncomfortable sensations in their legs (e.g., itching, pulling, creeping) that is helped or completely relieved by moving the legs. Symptoms usually get worse when still (e.g., sitting in a chair or lying in bed) and are usually worse at night. If you think you might have restless legs syndrome, complete a restless legs syndrome quiz and take it to your doctor.

What can shift-workers do to sleep well?
If you are a shift-worker, you will find it harder to sleep because it is bright outside and most other people are awake, adding to the noise of the day. To try to get a better sleep, make sure your room is dark. Use block-out curtains to reduce light as much as possible. Keep your room at a comfortable temperature, and sleep where it is quiet. If daytime noise disrupts your sleep, try ear plugs or a white-noise machine. Get answers to 6 common questions about shift work sleep disorder.

What should you do if you have trouble sleeping?
It's normal to have trouble sleeping every now and then, but if your trouble lasts for more than a few weeks and you're experiencing drowsiness during the day, you should see your doctor. Some medical conditions (e.g., reflux, arthritis, menopause, thyroid problems) can affect sleep, and your doctor will want to make sure they aren't contributing to your sleep problems. Your doctor will do a physical exam and ask you questions about your sleep. Together you will determine the best approach to deal with your sleeping woes. Find out the sleep symptoms that mean you should see a doctor.

Is melatonin effective for insomnia?
Melatonin may be helpful for improving sleep for jet lag, but it does not appear to improve daytime jet lag symptoms.

What is narcolepsy?
Narcolepsy is a condition where the sleep-wake cycle is disrupted. People with narcolepsy feel sleepy during the day and they may feel an almost irresistible urge to sleep during the day (e.g., while driving, eating) even though they have had enough sleep the night before. Read more about narcolepsy.