Insomnia most often stems from some other problem, such as a medical condition that causes pain or use of substances that interfere with sleep. Common causes of insomnia include:
- Stress. Concerns about work, school, health or family can keep your mind active at night, making it difficult to sleep. Stressful life events, such as the death or illness of a loved one, divorce, or a job loss, may lead to insomnia.
- Anxiety. Everyday anxieties as well as more-serious anxiety disorders may disrupt your asleep.
- Depression. You might either sleep too much or have trouble sleeping if you're depressed. This may be due to chemical imbalances in your brain or because worries that accompany depression may keep you from relaxing enough to fall asleep. Insomnia often accompanies other mental health disorders as well.
- Medications. Prescription drugs that can interfere with sleep include some antidepressants, heart and blood pressure medications, allergy medications, stimulants (such as Ritalin) and corticosteroids. Many over-the-counter (OTC) medications, including some pain medication combinations, decongestants and weight-loss products, contain caffeine and other stimulants. Antihistamines may initially make you groggy, but they can worsen urinary problems, causing you to get up more during the night.
- Caffeine, nicotine and alcohol. Coffee, tea, cola and other caffeine-containing drinks are well-known stimulants. Drinking coffee in the late afternoon can keep you from falling asleep at night. Nicotine in tobacco products is another stimulant that can cause insomnia. Alcohol is a sedative that may help you fall asleep, but it prevents deeper stages of sleep and often causes you to awaken in the middle of the night.
- Medical conditions. If you have chronic pain, breathing difficulties or need to urinate frequently, you might develop insomnia. Conditions linked with insomnia include arthritis, cancer, congestive heart failure, diabetes, lung disease, gastroesophageal reflux disease (GERD), overactive thyroid, stroke, Parkinson disease and Alzheimer's disease. Making sure that your medical conditions are well treated may help with your insomnia. If you have arthritis, for example, taking a pain reliever before bed may help you sleep better.
- Change in your environment or work schedule. Travel or working a late or early shift can disrupt your body's circadian rhythms, making it difficult to sleep. Your circadian rhythms act as internal clocks, guiding such things as your wake-sleep cycle, metabolism and body temperature.
- Poor sleep habits. Habits that help promote good sleep are called "sleep hygiene." Poor sleep hygiene includes an irregular sleep schedule, stimulating activities before bed, an uncomfortable sleep environment and use of your bed for activities other than sleep or sex.
- 'Learned' insomnia. This may occur when you worry excessively about not being able to sleep well and try too hard to fall asleep. Most people with this condition sleep better when they're away from their usual sleep environment or when they don't try to sleep, such as when they're watching TV or reading.
- Eating too much late in the evening. Having a light snack before bedtime is OK, but eating too much may cause you to feel physically uncomfortable while lying down, making it difficult to get to sleep. Many people also experience heartburn, a backflow of acid and food from the stomach to the esophagus after eating. This uncomfortable feeling may keep you awake.
Insomnia and aging
Insomnia becomes more prevalent with age. As you get older, changes can occur that may affect your sleep. You may experience:
- A change in sleep patterns. Sleep often becomes less restful as you age. You spend more time in stages 1 and 2 of non-rapid eye movement (NREM) sleep and less time in stages 3 and 4. Stage 1 is transitional sleep, stage 2 is light sleep, and stage 3 is deep (delta) sleep, the most restful kind. Because you're sleeping more lightly, you're also more likely to awaken. With age, your internal clock often advances, which means you get tired earlier in the evening and wake up earlier in the morning. But older people still need the same amount of sleep as younger people do.
- A change in activity. You may be less physically or socially active. Activity helps promote a good night's sleep. You may also be more likely to take a daily nap, which also can interfere with sleep at night.
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A change in health. The chronic pain of conditions such as arthritis or back problems as well as depression, anxiety and stress can interfere with sleep. Older men often develop noncancerous enlargement of the prostate gland (benign prostatic hyperplasia), which can cause the need to urinate frequently, interrupting sleep. In women, hot flashes that accompany menopause can be equally disruptive.
Other sleep-related disorders, such as sleep apnea and restless legs syndrome, also become more common with age. Sleep apnea causes you to stop breathing periodically throughout the night and then awaken. Restless legs syndrome causes unpleasant sensations in your legs and an almost irresistible desire to move them, which may prevent you from falling asleep.
- Increased use of medications. Older people use more prescription drugs than younger people do, which increases the chance of insomnia caused by a medication.
Sleep problems may be a concern for children and teenagers as well. Some children and teenagers simply have trouble getting to sleep or resist a regular bedtime because their internal clocks are more delayed. They want to go to bed later and sleep later in the morning.
