The amount of sleep a person needs depends on many factors, including age.

Sleep stages are divided into non-rapid eye movement (non-REM) and rapid eye movement (REM).

We all dream -- even if we don't remember it the next day. But why do we dream? And what do dreams mean, anyway?

Sleep hygiene is a combination of sleeping conditions and lifestyle habits that help you get consistent, uninterrupted sleep.

Insomnia is a sleep disorder that is characterized by difficulty falling and/or staying asleep.

Hypersomnia, or excessive sleepiness, is a condition in which a person has trouble staying awake during the day.

Parasomnias are disruptive sleep disorders that can occur during arousals from REM sleep or partial arousals from non-REM sleep.

With REM sleep behavior disorder, the paralysis that normally occurs during REM sleep is incomplete or absent.

 Bedwetting is most often a developmental issue. Most kids simply outgrow it and never need treatment.

When you wake up terrified from a disturbing nightmare, you might think you're the only adult who has them.

Sleepwalking symptoms aren’t as obvious as they may seem. Get the details here.

Have you ever felt like you were awake but unable to move? This condition is called sleep paralysis.

Learn about some of the most common sleep disorders.

Your partner may not be the only one missing out on a good night's rest. More than likely, your sleep is being affected, too.

What is the connection between sleep and your body's defense against illness and infection? It works both ways.

If high levels of unwanted stress are not properly managed, your health and sense of well-being can suffer.

Learn about specific sleep problems and steps in treating and diagnosing sleep problems.

A clinical trial is a program that tests the effectiveness and safety of various interventions in people with sleep disorders.

A sleeping pill may be effective at ending your sleep problems short-term.