How Does Stress Affect the Immune System
Mankind’s self-preservation is due to proper stress management. The human body’s reaction to stress is designed to protect itself against threats from aggressors or predators. Today, however, those kinds of threats are rare. Still, humans face daily life stressors when confronted with heavy workloads, academic pressures and family problems.
The Stress Response
In the face of danger, the brain initiates the flight-or-fight response. It signals the adrenal glands to release hormones such as cortisol and adrenaline, which increases heart rate and breathing and dilates blood vessels so that the blood can supply nutrients and oxygen to the muscles in the legs and the brain. And, for a short period of time, the immune system boosts its function presumably to help heal wounds possibly acquired from the flight or fight. Other bodily functions, such as digestion and growth are suppressed while in stress.
Once the perceived threat is gone, hormone levels normalize and the body’s systems resume their normal activities. For animals, this is an automatic psychological behavior. But when humans experience stress, they have difficulty in getting back to normal routines. The stressful situation will cause nightmares, sleepless nights, poor appetite, anxiety, and mood swings. These stress responses that are common only to humans are detrimental to the health.
Effects on the Immune System
Studies have confirmed the effects of stress on wound healing. For example, women who experienced chronic stress because of caring for a relative suffering from Alzheimer’s disease took 24% longer to heal small, dermal wounds. This is because the human stress response inhibits the secretion of pro-inflammatory substances called cytokines that are important in the healing process. This finding correlates with studies that have shown that fear or distress before surgery usually results in post-operative complications and longer hospitalizations.
Chronic stress has been shown to be associated with premature ageing. Substances that are associated with ageing could be seen in higher amounts in mothers caring for chronically-ill children and carers of spouses with dementia.
Furthermore, distressed individuals experience delayed responses to vaccines. The slow development of immune responses to pathogens results in higher rates of clinical illness. In a test on individuals exposed to rhinovirus, or the common cold, individuals who have recent stressful events developed cold symptoms faster than those who did not.
Evidence from animal and human studies has suggested that stress and depression can result in slower immune response that might lead to the progression of some types of cancer. Chronic stress affects important biological processes and increase DNA damage and somatic mutations that are believed to be involved in the onset of cancers.
The continual activation of the body’s stress response can disrupt almost all of the physiological processes and increases the risk of many health problems. Since stress is inevitable, the key to a longer life is proper stress management.
Common stress management strategies include having a healthy diet, regular exercise, enough sleep and developing a sense of humor. It is recommended to identify stressful situations and learn how to react to these.