Expanding on the thread about insomnia, here are some sleep disorders.
Maybe you have some.
How long can you hold your breath? People with sleep apnea may stop breathing in their sleep for up to 2 minutes or more! (They usually breathe just fine when they are awake.) This happens over and over again at night, making them sleep poorly and feel very tired in the daytime.
People with sleep apnea usually snore loudly.... Do you know anyone who snores?
Sleep apnea can affect the heart, so it is a serious medical condition. It is usually treated with a special breathing mask worn during sleep.
Delayed Sleep Phase Syndrome (DSPS)
People with this disorder can’t help staying up later and later each night, and waking up later and later each morning. They aren’t just being "night owls" by choice; something is wrong with their internal body clocks, making it impossible for them to stay in sync with the rest of the world. This problem is most common among adolescents and young adults.
The treatment usually consists of actually making the problem worse so it can finally get better.
(The opposite problem, getting sleepier earlier and earlier in the day is called Advanced Sleep Phase Syndrome. It is most common among senior citizens.)
Restless Legs Syndrome (RLS)
Do your legs ever feel uncomfortable at night? Some people describe the feelings as "itchy" or "restless" or "like creepy-crawlies under my skin." People with RLS often get up and walk around at bedtime, because their legs "just won’t settle down" and it helps to move them. RLS is usually treated with medication.
How long does it take you to fall asleep? People with insomnia consistently take longer than 30 minutes to drift off to sleep. Insomnia is one of the most common sleep disorders, and it is sometimes hard to cure. Practicing good sleep hygiene may help. Sometimes the advice of a doctor or counselor is needed.
Periodic Limb Movements in Sleep (PLMS)
Imagine that you fell asleep one night while someone was holding your shin. Let’s say after you fell asleep, that the person shook your leg every 20 seconds, for almost half the night! How do you think you would sleep?
A sleep disorder called Periodic Limb Movements in Sleep (PLMS) is just like that, except that the person’s own muscles are doing the shaking, rather than someone else doing it. It is usually treated with medication.
The symptoms of this rare disorder include extreme drowsiness, feeling weak at emotional times, and feeling paralyzed on the borders of sleep. Animals can have narcolepsy, too. Much of the research on narcolepsy has been done on dogs. And the "fainting goats" that are sometimes displayed at State Fairs actually have narcolepsy. In humans, narcolepsy is controlled with medication.
REM Sleep Behavior Disorder (RSBD)
Imagine what it would be like to act out your dreams, every night, while you were still sleeping! It would probably get you into some trouble, wouldn’t it? People who have RSBD do act out their dreams, and to make matters worse, their dreams tend to be more violent and aggressive than other peoples’ dreams. So they often hurt themselves, or those around them. Luckily, RSBD is quite rare.
There are many other kinds of sleep disorders, too: sleepwalking, night terrors, Jet Lag, Kleine-Levin Syndrome, bedwetting, head banging, night-time eating disorders, etc.
If you have a question about sleep disorders, or think you might know someone who has one, talk to your family doctor or a sleep specialist at an accredited sleep lab. Peachypants put up some links.
You can use this thread to discuss any of these in detail. Solutions, causes etc.
It also helps, simply to be aware of them.