Individuals are so preoccupied with the idea that they are or might become ill that they become very distressed and unable to function.
As a result, personal relationships and work performance deteriorate.
Individuals with illness anxiety disorder may or may not have physical symptoms.
If they have physical symptoms, the symptoms are mild, and individuals are more concerned about what their symptoms might mean (that is, that they have a serious disorder) than with the symptoms themselves.
Fear of illness is their main worry (If individuals also have significant physical symptoms, they may have somatic symptom disorder).
If individuals with illness anxiety disorder have a physical disorder, their anxiety is out of proportion to the seriousness of the disorder.
Some individuals examine themselves repeatedly. For example, they may check their pulse repeatedly to see if their heart beat is regular. They are easily frightened by new bodily sensations.
Some individuals with illness anxiety disorder seek medical care frequently. Others are too anxious to seek it.
Illness has a central place in their life and monopolises their conversation with others. They extensively research the disorder they think they may have. They are easily alarmed about illness, even in someone else.
Individuals with illness anxiety disorder repeatedly seek reassurance from family members, friends, and medical professionals.
When their medical professional tries to reassure them (for example, by telling them that examination and tests results are normal), they often think that the medical professional is not taking their symptoms seriously. Then they become more anxious. Often, their endless worrying is frustrating to others, resulting in strained relationships.
Affected individuals may then avoid situations that could result in more stress (such as visiting sick family members). They may also avoid activities that they fear may endanger their health (such as exercise).
Illness anxiety disorder tends to be chronic.
Symptoms may lessen, then recur.
Some individuals recover.