The exact cause of panic disorder is not clear. It is thought that panic disorder may result from an imbalance of chemicals in the brain (neurotransmitters).

Panic disorder also may be passed down through families (genetic). Children of parents who have panic disorder are up to 8 times more likely to develop panic disorder.³ You are also at a higher risk of developing panic disorder if you have a parent with either depression or bipolar disorder.^{4, 5} Stressors (such as the sudden loss of a relationship) may trigger symptoms of panic disorder as well.

You may experience a panic attack without having panic disorder. Panic attacks may be triggered by:

• Drinking large amounts of alcohol or abruptly stopping the use of alcohol.
• Drinking large amounts caffeinated beverages.
• Chain-smoking, which causes the amount of nicotine in the blood to be very high.
• Taking certain medications (such as those used to treat asthma and heart conditions) or abruptly stopping certain medications (such as those used to treat anxiety or sleep problems).
• Using illegal drugs, such as cocaine or marijuana.
• Having high levels of stress for a long time (chronic stress).
• Having recently had a baby.
• Having recently had surgery or been under general anesthesia.

Panic attacks also can be caused by or associated with other medical conditions, including:⁶

• Thyroid problems, such as an overactive thyroid (hyperthyroidism).
• Heart problems, such as mitral valve prolapse.
• Seizure disorders, such as epilepsy.
• Asthma.
• Respiratory problems, such as chronic obstructive pulmonary disease (COPD).
• Stopping the use of a prescription medication, such as a heart medication.
• Depression.
• Anxiety disorders such as post-traumatic stress disorder or obsessive-compulsive disorder.