Causes

The causes of anxiety disorders aren't fully understood. Life experiences such as traumatic events appear to trigger anxiety disorders in people who are already prone to anxiety. Inherited traits also can be a factor.

Medical causes

For some people, anxiety may be linked to an underlying health issue. In some cases, anxiety signs and symptoms are the first indicators of a medical illness. If your doctor suspects your anxiety may have a medical cause, he or she may order tests to look for signs of a problem.

Examples of medical problems that can be linked to anxiety include:

• Heart disease
• Diabetes
• Thyroid problems, such as hyperthyroidism
• Respiratory disorders, such as chronic obstructive pulmonary disease (COPD) and asthma
• Drug misuse or withdrawal
• Withdrawal from alcohol, anti-anxiety medications (benzodiazepines) or other medications
• Chronic pain or irritable bowel syndrome
• Rare tumors that produce certain fight-or-flight hormones

Sometimes anxiety can be a side effect of certain medications.

It's possible that your anxiety may be due to an underlying medical condition if:

• You don't have any blood relatives (such as a parent or sibling) with an anxiety disorder
• You didn't have an anxiety disorder as a child
• You don't avoid certain things or situations because of anxiety
• You have a sudden occurrence of anxiety that seems unrelated to life events and you didn't have a previous history of anxiety