Panic attacks occur when a person has distinct periods of intense fear and anxiety when there is no clear cause or danger. These symptoms come on suddenly and without warning. Panic attacks are a common anxiety-related disorder. Panic attacks can sometimes occur in otherwise normal, healthy people and will usually last for several minutes.
Physical symptoms that can occur during a panic attack include feelings of choking or suffocating, chest pain, nausea, shaking, sweating, pounding of the heart, and feeling dizzy or faint. Sometimes these symptoms are so intense that the person fears he or she is having a heart attack. Many of the symptoms of a panic attack can occur with other illnesses, such as hyperthyroidism, coronary artery disease, or chronic obstructive pulmonary disease (COPD). A complete medical examination may be needed before an anxiety disorder can be diagnosed.

People who have repeated unexpected panic attacks and worry about the attacks are said to have a panic disorder.