Estimates place the incidence of hypochondriasis in the general population at about 5%. Hypochondriasis occurs in men and women with equal frequency. It can begin at any age, even in children, but onset usually occurs between ages 20 and 30.

Although the cause of hypochondriasis is unknown, some research suggests an inherited susceptibility. It’s more commonly seen in individuals who suffered a serious illness as a child, who have a loved one who is seriously ill, who recently suffered a stressful event such as a death, who find it difficult to express emotions, and who have anxiety disorder. Few individuals fully recover.

The dominant feature of hypochondriasis is the misinterpretation of symptoms—usually multiple complaints that involve a single organ system—as signs of serious illness. As the medical evaluation proceeds, complaints may shift and change. Symptoms, which can range from specific to general, typically are associated with a preoccupation with normal body functions.

The hypochondriacal patient will relate a chronic history of:

• waxing and waning symptoms

• excessive concern about a body part or system

• anxiety or depression

• frequent changing of health care providers

• belief that the diagnosis of the health care provider is wrong

• excessive concern about illness that interferes with his social, family, and occupational functioning

• unfounded belief that he’s especially vulnerable to disease

• multiple evaluations and diagnostic testing for similar symptoms.