Anxiety can also be caused by a general medical disorder or the use or discontinuation (withdrawal) of a drug.
General medical disorders that can cause anxiety include the following:
- Heart disorders, such as:
- Heart failure; and
- Abnormal heart rhythms (arrhythmias)
- Hormonal (endocrine) disorders, such as:
- An overactive adrenal gland (hyperadrenocorticism); or
- Thyroid gland (hyperthyroidism); or
- A hormone-secreting tumour called a pheochromocytoma.
- Lung (respiratory) disorders, such as:
- Asthma; and
- Chronic obstructive pulmonary disease (COPD).
Even fever can cause anxiety.
Anxiety may occur in dying people as a result of fear of death, pain, and difficulty breathing.
Drugs that can trigger anxiety include the following:
- Stimulants (such as amphetamines);
- Many prescription drugs, such as corticosteroids; and
- Some over-the-counter weight-loss products, such as those containing:
- The herbal product guarana;
- Caffeine; or
Withdrawal from alcohol or sedatives, such as benzodiazepines (used to treat anxiety disorders), can cause anxiety and other symptoms, such as insomnia and restlessness.