Many medical studies have linked chronic stress to numerous illnesses and problems. In fact, five of the leading causes of death in the United States are linked to stress: heart disease, cancer, lung ailments, cirrhosis of the liver, and suicide. Women are affected as much as men, often more so. Stress respects no particular sex, race, religion, or nationality.
It is well known that stress can impair the functioning of the body’s immune system. When immune-system suppression occurs, the body becomes much more vulnerable to infections, both viral and bacterial, as well as to other opportunistic pathogens, such as parasites.
The immune system also plays a major role in impeding many types of cancer. With an impairment or compromise to our immunological defense mechanisms, the ability to ward off or fight cancer cells is correspondingly suppressed, and this can lead to catastrophic consequences. We become more vulnerable to cancer and its spread, and to other chronic medical conditions that interact with our immune system.
It is not just a myth that people who are in love get sick less often. Those in this state tend to be happier and more optimistic. They are not as bothered by the usual stressors in our environments and in our lives. In their transcendent zone of love, they rise above mundane conflicts. When someone is in love, their immune system functions at an optimal level, providing them protection from invading germs, cancer cells, or other attacks on their health.
Stress seems to increase levels of LDL cholesterol, the so-called bad cholesterol linked to increased risks of coronary artery disease. Other studies have demonstrated that sudden mental stress causes the inner layer of blood vessels to constrict, thereby increasing the risk of heart attack or stroke.
The New England Journal of Medicine, widely considered to be the foremost general medical journal in the United States, published a major article in January of 1998 detailing the multi-system damage that chronic stress can inflict on the human body. In addition to heart disease and immune-system dysfunction, the study cited memory loss, insulin resistance, and decreased bone-mineral density (osteoporosis, which leads to weakness of bone and increased likelihood of fractures).
High levels of cortisol can increase appetite and lead to obesity. Prolonged cortisol secretion can trigger increased insulin production. Insulin, a powerful appetite stimulant, also causes increased fat storage, particularly around the waist. In a study at Yale University, women who stored fat primarily in their abdomens were compared to women who stored fat mostly in their hips. The women with abdominal fat reported feeling more threatened by stressful tasks and having more stressful lives. They also produced significantly higher levels of cortisol than the other groups of women. Interestingly, fat cells deep in the waist area are very rich in stress hormone receptors, and a Harvard Medical School study found that abdominal fat was positively correlated with an increased risk of coronary heart disease.
Stress can suppress the reproductive system and impair fertility. The production of the male and female sex hormones, testosterone, estrogen, and progesterone, can be inhibited as well. Prolonged HPA axis activation also inhibits the secretion of growth hormone, essential for normal growth.
Numerous studies have linked stress—especially chronic stress—to depression and increased incidences of suicide attempts. These patients also have higher levels of CRH, the hypothalamic stress substance. Other medical and psychological conditions associated with elevated CRH include obsessive-compulsive disorder, anorexia nervosa, several types of anxiety syndromes, alcoholism, diabetes, thyroid disorders, and certain forms of insomnia.
