Somatization is the experience of medical and somatic (physical symptoms) that don't appear to have an organic cause within the organism. This is the mental representation of physical symptoms. Somatization can be a conscious action (such as in the case of malingering: pretending to have medical symptoms in order to gain something) or entirely unconscious (like hypochondriasis).
These types of disorders are known as somatoform disorders. Hypochondriasis (sufferers are called hypochondriacs) believe that their normal physical sensations are symptoms of deadly infection and diseases. They will perceive a simple headache as a brain tumor and a cough to having tuberculosis. Hypochondriacs and malingerers use up a largely disproportionate amount of medical resources and finances. Somatization can also be seen in somatization disorder in which symptoms include physical problems that are felt, but are not associated with a medical problem.
An example of this could be a person suffering from severe headaches that are related to stress, rather than any organic cause. This practice becomes disruptive to the sufferer and those around them. It is important that the symptoms being reported cannot be explained by medical conditions or by substance use.