Some studies have shown an association between stress and certain types of cancer, including gastric, breast, lung and colorectal. To date, research indicates that relatively recent life events of five to 10 years preceding diagnosis are the ones associated with the onset of cancer. Some researchers have concluded that the sequence leading to cancerous tumors is sparked by environmentally induced stresses of a chemical, radiological or some other origin. Experts agree that more studies are needed to determine the precise relationship between stress and cancer. Gastrointestinal disorders Ulcers.
Many people believe that stress causes ulcers.
Stressful events, whether they are acute or chronic, are more strongly associated with ulcers if they contain a component involving personal threat or frustration of important life goals. This is a common disorder of the intestines that leads to cramping, gas, bloating and changes in bowel habits, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Experts are still studying the exact cause of IBS, but they think that stress may worsen the symptoms. One report notes that people who have IBS may in turn react to acute stress more markedly. There is some controversy over whether stress contributes to infections.