What Causes Insomnia?

Secondary Insomnia

Secondary insomnia is the symptom or side effect of another problem. This type of insomnia often is a symptom of an emotional, neurological, or other medical or sleep disorder.

Emotional disorders that can cause insomnia include depression, anxiety, and posttraumatic stress disorder. Alzheimer's disease and Parkinson's disease are examples of common neurological disorders that can cause insomnia.

A number of other conditions also can cause insomnia, such as:

• Conditions that cause chronic pain, such as arthritis and headache disorders
• Conditions that make it hard to breathe, such as asthma and heart failure
• An overactive thyroid
• Gastrointestinal disorders, such as heartburn
• Stroke
• Sleep disorders, such as restless legs syndrome and sleep-related breathing problems
• Menopause and hot flashes

Secondary insomnia also may be a side effect of certain medicines. For example, certain asthma medicines, such as theophylline, and some allergy and cold medicines can cause insomnia. Beta blockers also may cause the condition. These medicines are used to treat heart conditions.

Commonly used substances also may cause insomnia. Examples include caffeine and other stimulants, tobacco or other nicotine products, and alcohol or other sedatives.

Primary Insomnia

Primary insomnia isn't a symptom or side effect of another medical condition. This type of insomnia usually occurs for periods of at least 1 month.

A number of life changes can trigger primary insomnia. It may be due to major or long-lasting stress or emotional upset. Travel or other factors, such as work schedules that disrupt your sleep routine, also may trigger primary insomnia.

Even if these issues are resolved, the insomnia may not go away. Trouble sleeping may persist because of habits formed to deal with the lack of sleep. These habits may include taking naps, worrying about sleep, and going to bed early.

Researchers continue to try to find out whether some people are born with a greater chance of having primary insomnia.