Hypochondriasis

One type of somatoform disorder is hypochondriasis, in which people have a constant fear of illness and a preoccupation with their health. These individuals believe that everyday aches and pains are symptoms of a dread disease. It is not that the “symptoms” are faked; rather, it is the misinterpretation of those sensations as evidence of some serious illness – often in the face of inarguable medical evidence to the contrary – that characterizes hypochondriasis.

Hypochondria is neurotic concern for one's health.