The genetic contribution to<unk>  is probably moderate, with heritability estimates around 10-37%. Non-shared environmental factors (i.e., experiences that differ between twins in the same family) explain most of the variance in key components of the condition such as the fear of illness and disease conviction. In contrast, the contribution of shared environmental factors (i.e., experiences shared by twins in the same family) to<unk>  is approximately zero. Although little is known about exactly which non-shared environmental factors typically contribute to causing<unk> , certain factors such as exposure to illness-related information are widely believed to lead to short-term increases in health anxiety and to have contributed to<unk>  in individual cases. Overly protective caregivers and an excessive focus on minor health concerns have also been implicated as potential causes of<unk> . In the media and on the Internet, articles, TV shows, and advertisements regarding serious illnesses such as cancer and multiple sclerosis often portray these diseases as being random, obscure, and somewhat inevitable. In the short term, inaccurate portrayal of risk and the identification of non-specific symptoms as signs of serious illness may contribute to exacerbating fear of illness. Major disease outbreaks or predicted pandemics can have similar effects. There is anecdotal evidence that it is common for serious illnesses or deaths of family members or friends to trigger hypochondria in certain individuals. Similarly, when approaching the age of a parent's premature death from disease, many otherwise healthy, happy individuals fall prey to hypochondria. These individuals believe they are suffering from the same disease that caused their parent's death, sometimes causing panic attacks with corresponding symptoms.
Hypochondriasis
Panic disorder
Autoeczematization
Generalized anxiety disorder
Psychopathy
Obsessive–compulsive disorder
Identity disorder
Agoraphobia