STRESS AND ILLNESS
Research has shown strong links between prolonged stress and many disorders, mentally and physically. The immune system is easily affected by stress.
Stress can cause: Cancer, Colds and Flus, Heart Disease, Eczema and Skin Problems, Depression, Stomach Ulcers, Post-Traumatic Stress Disorders, Asthma
Too much stress can lead to behaviours, such as smoking or overeating, which increases the risk of serious illness - so the link with the original source of stress is indirect. The incidence of cancer has been correlated with high stress levels.
Jacobs and Charles (1980) found that cancer patients - for example, child cancer patients, often suffered high levels of stress before the diagnosis of their illness.
Tache et al (1979) found the incidence of cancer to be higher in those with a poor 'social support network' such as the widowed, divorced or separated.
It is difficult to rule out that undetected, developing cancer might cause stress, rather than stress due to external factors leading to cancer.