Hypochondriasis is a mental disorder associated with an excessive worry about one's health and a preoccupation with a variety of symptoms whereby the person is convinced he/she is suffering from some sort of disease. Patients suffering from this condition mostly seek medical attention searching for the physician that will diagnose them with a physical illness to explain their symptoms. This often leads to a variety of excessive work-ups, including many repetitive and expensive lab tests and diagnostic procedures. Even though these are necessary to rule out some serious physical disease, this diagnosis should not be made by exclusion alone, but should also be made by using inclusive criteria as mentioned below.

• System(s) affected: Nervous
• Genetics: Some studies show an increase prevalence of hypochondriasis in families, especially among identical twins and first degree relatives.
• Incidence/Prevalence in USA:
  • Some studies point out that hypochondriasis is present in 3-14% of patients seen by primary care physicians.
  • Some surveys show that 10-20% of the general population worry about illness from time to time. About 45% of patients seen by mental health professionals worry about illness from time to time.
• Predominant age: The peak incidence is believed to happen during the fourth or fifth decade of life, although all age groups can be affected, including children, adolescents, and the elderly.
• Predominant sex: It is found equally in men and women; however, women tend to seek help more often than men

• Preoccupation with fears of having, or the idea that one has, a serious disease based on the person's misinterpretation of bodily symptoms
• The preoccupation persists despite appropriate medical evaluation and reassurance
• The belief is not of delusional intensity (as in delusional disorder, somatic type) and is not restricted to a circumscribed concern about appearance (as in body dysmorphic disorder)
• The preoccupation causes clinically significant distress or impairment in social, occupational, or other important areas of functioning
• The duration of the disturbance is at least 6 months
• The preoccupation is not better accounted for by generalized anxiety disorder, obsessive-compulsive disorder, panic disorder, a major depressive episode, separation anxiety, or another somatoform disorder

• Biological: There is some evidence suggesting that patients with hypochondriasis may be born with a tendency to amplify somatic sensations and that they have lower threshold and a lower tolerance of physical discomfort
• Life events: Medical diseases may predispose a patient to hypochondriasis, such as certain patients being highly sensitive to certain physical symptoms following an acute stroke, myocardial infarction, intensive treatment following malignant illness, organ transplantation, etc. These may be experienced by the patient or by a close family member or friend
• Childhood events: The experience of numerous or serious actual medical illnesses during one's childhood may predispose the individual to hypochondriasis later on in life
• Psychological: Many authors view hypochondriasis as the patient's psychodynamic defense against guilt, shame, low self-esteem, and a narcissistic over-indulgence with one's self. Other authors view it as the patient's way of seeking attention by overly identifying with the sick role which offers the patient a way to alleviate symptoms of anxiety and seek reassurance
• Sociocultural: Some societies and cultures view mental symptoms in a pejorative and stigmatized way, blaming the patient for his/her illness, however, if the patient has physical symptoms and a bona fide medical diagnosis, he/she is treated with greater empathy, dignity, and respect and is not blamed for causing their illness

Exposure to life-threatening medical conditions and procedures in one's childhood, adolescence, or in adult life