The Most Common Causes of Insomnia

5. Medication

All medications have side effects, and insomnia is common to a few drugs. Some cold and allergy medicines contain pseudoephedrine which has a stimulating effect that can cause insomnia. Antidepressants can make it difficult to fall asleep, too.

Doctors commonly prescribe beta-blockers for high blood pressure and other heart problems, but they also lower the amount of melatonin secreted by the body, leading to sleep changes. Another class of drugs that causes insomnia is corticosteroids. Studies show that sleep disorders with insomnia and restlessness occurred in 73 percent of participants taking a corticosteroid.