How Stress Affects the Body

Medical Reviewer

Stress is known to affect the body in ways that leave the person vulnerable to illness. In this Sharepost I provide a brief overview of what happens to the body when it is exposed to stress over the longer term. The effects of chronic stress result in wear and tear to the body that ultimately leads to heart disease, infections and exposure to range of diseases.

Our natural defence mechanisms are geared to deal with circumstances that require a fairly immediate and relatively short-term response. This 'fight or flight' system is important for our wellbeing and survival, but problems arise when we are involved in situations that maintain our stress response. Prolonged activation of the sympathetic nervous system can result in an increased heart rate, high blood pressure, the formation of blood clots, fatty deposits and suppression of the immune system.

Stress also triggers changes in the body that result in increased levels of corticosteroids, the most important of which is cortisol. Prolonged production of cortisol can lead to nerve damage to the brain and can decrease immune function. In turn, these changes increase the chances of infection, memory loss, concentration and mental health problems.

The effects of stress on the body tend to be studied in one of two ways. The first is by looking at the effects of acute stress and the second by studying the effects of chronic stress. Acute stress is associated primarily with changes to blood pressure, heart rate and activity relating to activation of the sympathetic nervous system, previously mentioned. Chronic stress is more likely to involve the release of cortisol and the slower build up of atherosclerosis and damage to the cardiovascular system.

Although it is possible to consider the effects of stress as having a direct effect on the body, the reality is actually very different and rather more complex. We know that stress changes people's behavior and this can result, for example, in an increase in smoking, alcohol consumption, dietary change and reduced physical activity. These behaviors, in isolation and in combination, have their own effect on the body, so separating out the direct from the indirect effect of stress becomes a fairly complex task.