Excessive, or abnormal, health anxiety is a form of anxiety focused on the belief of having, or fear of getting, a serious illness. The belief or fear is usually concerned with a medical illness and occurs without sufficient evidence of organic pathology to account for the symptoms, and despite medical reassurance. Both health anxiety and organic illness can coexist. For diagnostic purposes, health anxiety is normally not regarded as pathological until it has lasted for at least 6 months.

Worrying about health is a normal protective function. For example, in someone with a history of chest pain due to angina, the natural concern arising from more frequent attacks may prompt a medical consultation which could avert an impending myocardial infarction. Health anxiety becomes maladaptive when it is out of proportion to the medical risk. This could represent either a low level of anxiety when the risk is high, as, for example, indulging in frequent episodes of unprotected sex with many partners, with little or no consideration of the risk of acquiring a sexually transmitted infection, or experiencing excessive worry about a potential medical problem when in fact the risk of developing that condition is normal or very low.

Severity may range from mild concern to severe and constant preoccupation. The problem may also be transient; from time to time we all experience health anxiety which subsequently resolves, but for some it may become chronic and debilitating and cause severe suffering, which unfortunately in many cases becomes persistent.

The term ‘health anxiety’ is increasingly being used to describe patients with hypochondriasis. Its main advantage over hypochondriasis is that as well as being more accurate, it is less pejorative and therefore more acceptable to patients and makes it easier to broach the diagnosis. It is used throughout the text in this handbook, and is likely to become a formal diagnosis in the near future. In patients with this condition, preoccupation with health arising from cognitions based on the misinterpretations of bodily sensations and changes, generates a range of distressing emotions.