If you have problems with your sleep, you have problems with your health. Not getting enough restful sleep each night can result in a long list of health problems, including forgetfulness, fatigue, a weakened immune system, high blood pressure, diabetes and heart disease. Research has found that workers with sleep problems are twice as likely to have an accident resulting in injury on the job, while a recent British study discovered that adults who get less than six hours of sleep every night are 12 percent more likely to die early.

There are three main types of sleep problems. Insomnia is the inability to fall asleep easily, or to remain asleep. Disturbed sleep means waking up frequently, and can be the result of conditions such as restless legs syndrome or sleep apnea, characterized by shallow or stopped breathing. Narcolepsy is uncontrollable sleep: those suffering from this rare condition fall asleep without warning during the day.

Occasional sleeplessness is normal, especially if you can pinpoint the cause, such as a stressful day. What isn't normal is long-term restlessness that leaves you feeling groggy or tired throughout the day. Sleep isn't just unconsciousness; it's the time when the body repairs itself, and the information you took in during the day is "filed" into your memory banks. If you don't get enough sleep, your health starts to deteriorate, and your memory becomes foggy.

In our fast-paced society, many people pride themselves on how little they sleep, using that time to cram in other activities. Eventually, their poor sleeping habits will come back to haunt them. Children generally sleep the most, and older adults the least, but on average, adults need between six to nine hours of restful sleep each night to stay sharp, focused and healthy.

When looking at the causes of sleep problems, it's important to differentiate physical reasons from external ones. Although you might not realize it, your restlessness may be caused by such things as a partner's snoring, a bedroom that's too hot, too cold or not dark enough, or disturbance from children or pets, especially if you let your dog or cat sleep in your bed. Sexual activity can go either way: some sleep soundly afterwards, while others end up wide awake.

Stress may be keeping you from falling asleep, and for women, menopause is a frequent cause of insomnia, especially during hot flashes or night sweats. Too much caffeine or a large meal before bedtime can be to blame, and while alcohol can make you tired, it interferes with the quality of sleep. Fluids of any type just before bed may present a problem: that big mug of chamomile tea may make you sleepy, but you'll be up halfway through the night to empty your bladder. Certain medications can also disrupt sleep.

As many as 12 million or more Americans are thought to suffer from restless legs syndrome (RLS), a neurological disorder that causes unpleasant sensations in the legs, and sometimes the arms. It results in an uncontrollable urge to move the limbs, especially when lying down and relaxing, such as when trying to sleep. Most people with RLS also experience involuntary leg twitching or jerking, which further keeps them from sleeping.

Some 18 million Americans have sleep apnea, half of whom may not realize it. The breathing stops or becomes very shallow during sleep, causing the sleeper to wake up and start breathing again. This condition can be serious or even potentially life-threatening.

In many cases of sleeplessness, the cure can be simple: a heavy blind to make the room darker, keeping pets out of the bedroom, or limiting how much you eat or drink before bed. Regular exercise helps improve the quality of sleep, as long as you don't work out too soon before going to bed. Even a brisk walk in the afternoon will help considerably.

Setting a "sleep routine" will often help. Set regular times for going to sleep and waking up. Shut off the computer or other distractions and start winding down a couple of hours before bedtime. Some people find that reading in bed for a half-hour or so will bring on sleepiness, but the words should be on paper only: don't spend bedtime catching up on emails.

Prescription sleep medications may help temporarily, but use them only on your doctor's advice. They can cause dependency and make the problem worse. Over-the-counter sleep medications contain antihistamines, which can make you feel groggy the next day and interfere with regular sleep patterns.

Restless legs syndrome (RLS), which can prevent falling or staying asleep, may occur on its own or be related to such conditions as low iron levels, kidney disease, thyroid problems, alcohol use or Parkinson's disease. The causes of RLS still aren't entirely understood, and so remedies often depend on "what works." For mild cases, doctors usually recommend exercise, massage or a warm bath. For more severe cases, either prescription medications or dietary supplements often provide relief.

Sleep apnea is generally caused by physical conditions such as excess weight, nasal blockage, or airway shape. Losing weight or elevating the head may help; for serious cases, a mechanical device called CPAP (continuous positive airway pressure) keeps the airway open during sleep.