Instead of counting sheep, try tallying the many things that can cause insomnia, such as sleeping pills, nighttime noshing, stress and hormonal changes.

If its been years since you slept like a baby, youre not alone: An estimated 25 to 30 percent of American adults suffer from insomnia. The figures are even greater for people over 65. Men start out with a higher rate of sleep issues, but women catch up to them by around age 50.

Here are eight reasons youre having trouble reaching, or staying in, the Land of Nod and what you can do about it:

1. Youre stressed.

Stress keeps you revved up and interferes with the biological processes that would normally help you fall asleep at the end of the day. Cognitive behavioral therapy for insomnia (CBT-I), a branch of cognitive behavioral therapy targeted to those with sleep issues, is especially helpful for tense people and is the first-line treatment for most sleep disorders.

This is a regimented program, with five to six sessions, says Dr. Joseph Andrew Berkowski, a neurologist at the University of Michigan.

A sleep psychologist trained in CBT-I may, for instance, ask you to keep a sleep diary, recommend avoiding naps, train you to get out of bed when you cant sleep and help you change thoughts that may make it hard to nod off.

This is by far the most effective long-term therapy for people with chronic insomnia, those with sleep problems on a night-to-night basis, Berkowski says.

However, theres a scarcity of CBT-I practitioners in the U.S. most are clustered at major academic and VA medical centers. But recently, research has validated the efficacy of CBT-I done remotely by computer. In the November, 2016 issue of JAMA Psychiatry, an analysis of SHUTi ($135), a six-week online course, found that the treatment helped participants fall asleep more quickly and stay asleep longer both shortly after the program and a year later. A London-based program called Sleepio ($300) has also received some validation in studies.

2. You get up at different times during the week.

If you have a consistent routine, your sleep will be of higher quality and youll feel better in the day, says Berkowski. But many people with regular jobs sleep late on weekends to make up for what they miss during the week, resulting in insomnia when they go back to work.

Erratic sleep schedules can also happen when people retire and no longer adhere to a rigid timetable, says Dr. Karl Doghramji, medical director of the Jefferson Sleep Disorders Center at Thomas Jefferson University.

The solution is to awaken at the same hour each day. The time you go to bed is not as important as the time you wake up, because thats when the bodys clock starts, Berkowski notes.

3. Youre a woman near or past age 50.

The hormonal changes leading up to menopause, which typically occurs at 51, can have a big effect on womens sleep quality.

Progesterone is a sleep-promoting hormone and its decline can make it harder to fall asleep, according to Dr. Ritu G. Grewal, a sleep medicine physician at Thomas Jefferson University. The shifting ratios of estrogen and progesterone, both of which eventually drop precipitously, can lead to sleep-disturbing hot flashes.

Hot flashes and menopause-related insomnia can be treated with hormone therapy, usually consisting of estrogen and progesterone. Since hormone therapy has been connected with breast cancer, the conventional advice is for women to take it for only three years after menopause, Grewal notes.

4. You have sleep apnea.

If you snore loudly and wake up a lot, you may have sleep apnea. In this condition, you stop breathing several times during the night, depriving your body of oxygen.

Obstructive sleep apnea (OSA), the most common form, happens when theres an obstruction in the back of your throat, such as collapsed soft tissue, that interferes with air flow. OSA is a serious condition associated with daytime fatigue, high blood pressure and heart disease.

After menopause, womens rates of OSA really shoot up and become equal to mens, partly because the drop in progesterone loosens throat muscles.

Fortunately, sleep apnea is one of the easiest sleep conditions to treat, Berkowski says. The most effective way is with a machine called Continuous Positive Airflow Pressure (CPAP) that blows air down your throat while youre sleeping.

5. Youre depressed.

Depression defined by the Mayo Clinic as persistent feeling of sadness and loss of interest is one of the most common causes of insomnia.

Most often people wake up early in the morning, though some depressed people may also have trouble falling asleep, says Doghramji. He adds that depression can be successfully treated with antidepressants and talk therapy.

6. You take over-the-counter sleep medications.

In general, over-the-counter drugs, those with PM in the name, contain antihistamines, which are engineered to treat allergies, not insomnia, says Berkowski. They can make you feel drowsy the next day and usually stop working after being taken a few days in a row.

If you really feel the need for a sleep medication, he says, youre better off with newer prescription drugs like Lunesta that are tailored to sleep problems and wont leave you foggy the day after.

They can be effective for months, but then they will probably stop working, too, Berkowski says. Prescription drugs work better when used occasionally rather than on a continuing basis.

For chronic insomnia, youre better off with CBT-I. It has a longer effect than medications, notes Doghramji.

7. You eat too close to bedtime.

Gastroesophageal reflux disease (GERD), in which stomach acid backflows into the esophagus, is one of the most common causes of disrupted sleep in Americans between the ages of 45 and 64, according to the National Sleep Foundation.

Most patients with GERD experience an increase in the severity of symptoms (usually heartburn or coughing and choking) while sleeping or attempting to sleep, the organization states.

There is a wide range of foods that can cause reflux and, for any particular person, the list can be idiosyncratic, Doghramji notes. Food may be producing reflux without youre being aware of that happening.

One way to protect yourself, he adds: Dont eat within four hours of bedtime because it takes that much time for food to clear the stomach.

8. You dont turn off your electronic screens.

Too much exposure to the blue light of electronic screens can shift your natural circadian rhythm and depress levels of melatonin, a hormone that helps regulate sleep.

The Harvard Health Letter recommends the following:

• Avoid spending time on your cell phone, computer or iPad beginning two to three hours before bed.
• If you work overnight or must use electronic devices, consider wearing blue-blocking glasses or installing an app that filters the blue/green wavelength.

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