One of the many effects of chronic unpredictable stress on the body is the elevation of cholesterol and triglyceride levels. When stressed out, people tend to have higher levels of these two lipids. In addition to this, the levels of the inflammatory cytokines also rise. These cytokines are linked to the activation of the pro-inflammatory enzyme, which in turn increases the levels of cholesterol in the blood.
Another effect of stress on the body is that it can trigger the development of cardiovascular disease. When a person is continuously exposed to high levels of stress for prolonged periods, their body begins to adapt by weakening its ability to process and handle stress as well as decreases the strength and flexibility of its immune system. When this happens, inflammation occurs in the arteries and the heart becomes compromised.
The increased blood pressure and the weakened heart can lead to a variety of negative effects on the physical health of an individual. Not only does this translate to increased morbidity and disability, but it can also lead to the onset of heart disease and stroke. In addition, the increased triglyceride level in the blood is directly linked to the increased levels of physical stress. A study conducted by Duke University demonstrated that those who are always feeling good were not only less likely to suffer from coronary artery disease; they also exhibited improved cardiovascular health. Other studies have supported these findings by showing that stress reduction is directly correlated to improved survival and reduced hospitalization for high blood pressure.
Stress affects a person's mental health. When under acute stress, the brain releases chemicals such as cortisol, a stress hormone, into the bloodstream. Cortisol acts as a calming mechanism and helps the body return to a state of normalcy. However, when the body is constantly exposed to prolonged stress, the brain's natural calming mechanisms are not sufficiently developed and the adrenal glands are over stimulated, which results in the release of even more stress hormones into the bloodstream.
There are several additional negative effects of stress on the body that are not directly related to the symptoms of high blood pressure. Individuals who are regularly stressed may experience insomnia, memory loss, headaches, gastrointestinal problems and muscle tension. These physical changes are felt in the cardiovascular system, which weakens the heart and increases the risk of cardiac arrest or stroke. Chronic stress also contributes to digestive disorders such as irritable bowel syndrome, ulcers and gastritis.
In addition to the physical effects of stress on the body, certain types of cancer have been linked to such conditions as chronic unpredictable stress. These rodents were exposed to high amounts of stress in order to test the effects on the animals' health. During the study, the rats were placed in stressful situations for extended periods of time and their bodies were examined after a period of weeks. After testing, it was found that the rats' testes were damaged and this resulted in them developing testicular tumors.
The research is preliminary at this point and there is no clear conclusion regarding whether the testicular tumors are caused by the long-term exposure to chronic stress. However, the scientists noted that the testes of these older rats were significantly larger than the controls. In addition, it appears that chronic stress has a domino effect on the body and specifically, the brain. The researchers believe that the increased size of the testes was due to the cortisol, which is a hormone produced when the body is under stress, binding to the cell membranes of the testes. While this has been shown to have an effect on tumors in human cancers, this study did not directly focus on the effect of cortisol on tumors in younger rats which makes the current study all the more important.