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What It Isn't

Maybe you regularly stay out late because you love a good party, and now (surprise!) you're tired. Or you're at the office until the wee hours to get ahead at work. Those aren't examples of insomnia. Insomnia is when you can't fall asleep, even though you want to, or you can't stay asleep long enough.

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Stress

Events like a job loss or the death of a loved one often cause some sleepless nights. Your doctor might call it acute insomnia as long as it goes away on its own within a few nights. Long-term worry, as well as anxiety disorder, panic attacks, and PTSD, can lead to chronic insomnia, which is more serious.

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Irregular Sleep Times

A confused body clock can keep you up when it's time for bed. Perhaps that's the result of an inconsistent bedtime, a long flight from another time zone, working overnight, or changing shifts for your job. Some people simply have a different circadian rhythm that puts them out of sync with typical activities, so it's hard for them to sleep at "normal" times.

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Mental Illness

A troubled mental state plays a role more than half of the time. People with depression are far more likely to have sleep problems, including insomnia. So are those with anxiety, bipolar, and obsessive-compulsive disorders. The way your sleep is affected can offer clues to the type of illness. It's not uncommon to be diagnosed with a mental disorder after you seek help for insomnia.

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Breathing Problems

Heavy snoring could be sleep apnea, which cuts off your breathing and could wake you hundreds of times in a single night. You may not remember it, but you might feel groggy the next day. Sometimes it's related to your weight, but not always. Nasal allergies and asthma also could interfere with your breathing. A doctor can test you for these conditions, and help you manage and treat them.

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Dementia

Along with loss of memory, Alzheimer's and other forms of dementia can unsettle some people when you'd normally expect them to sleep, and they get restless. It's known as "sundown syndrome" or "sundowning." The person may be confused, anxious, restless, or aggressive around bedtime, and start to pace, rock, or even wander off. Sometimes this behavior fades, but sometimes it keeps them awake all night.

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Pain

Whether from arthritis, chronic back issues, fibromyalgia, cancer, or another condition, pain can prevent you from peacefully drifting off or interrupt your rest. And to complicate the issue, sleeplessness can make pain hurt more as well, creating a cycle. You may need to deal with the symptoms separate from the illness that’s behind them.

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Itching

Conditions like psoriasis and eczema can make your skin burn and itch so badly that it's all you can think about. No amount of counting sheep will distract you. And if you do fall asleep, you might scratch so hard it wakes you up again! Fortunately, there are things you can do to soothe your skin. If you don't know what's causing the itch, it's best to see your doctor.

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Parkinson's Disease

People with this disease tend to sleep less and wake up more often than others of a similar age. It interferes with brain and nerve signaling, and you're more likely to have sleep apnea and to get up to pee. The condition also seems to disrupt the important REM sleep stage. Related anxiety and depression can lead to sleep problems, too. But medications that help you sleep may cause added confusion for some with Parkinson's.

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Menopause

Usually in middle age, a woman's body slowly stops making progesterone and estrogen. The shifting balance of hormones, as well as other changes that typically happen in life at this time, can make you more sensitive to things like stress that affect sleep. Severe hot flashes -- surges of adrenaline that raise your body temperature -- could be so uncomfortable that you wake up drenched in sweat, sometimes several times a night.

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Medications

Drugs for allergies, heart disease, hypertension, thyroid problems, and depression -- especially SSRIs like fluoxetine (Prozac) -- might cause insomnia. Meds for ADHD and Parkinson's disease can also keep you up, along with the pseudoephedrine found in many over-the-counter decongestants. Check with your doctor about adjusting or changing your medication if you think it affects your sleep.

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Primary Insomnia

This means there doesn't seem to be anything about your environment, physical health, or mental well-being that would cause sleep problems. Doctors think some people's brains simply stay more alert -- too alert -- when they should be sleeping. It's not yet clear, but this could be the result of some physical difference, possibly genetic, in the brain. Scientists continue to study the possible causes.

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What Insomnia Does to You

Lack of sleep can make you moody, cranky, anxious, and depressed. It could also be harder to think straight or remember things. And you're more likely to have an accident in your car or elsewhere that could injure you or someone else. Insomnia is linked to conditions like obesity, high blood pressure, diabetes, and heart disease, too.

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What May Help

To help get your sleep cycle on track, start with your bedroom. It should be dark, quiet, safe, comfortable, and cool. Avoid caffeine; even in normal doses, it can cause insomnia. Consider a hot bath, reading, or light stretching before bed. Avoid loud activities and difficult discussions, as well as heavy, fatty foods. Exercise earlier in the day, and get some sunlight in the morning.