Learn About Stress-Induced Infectious Diseases

Severe, prolonged chronic stress has negative effects on the human body, including increasing the risk of becoming sick from infections.

Can Stress Really Increase Your Risk for Infections?

Studies have shown that people with greater levels of continuous stress are more prone to getting some infectious diseases.

It is important to note, however, that stress levels differ from person-to-person, due to individual differences in a person’s emotional and physiological makeup. Therefore, a situation that causes significant stress for one person may or may not have the same effect on another.

What Happens to Your Body When You Are Stressed?

• Acute stress response: The acute stress response is an immediate response to a stressful event. The body’s immediate response is to release stress hormones, which help the body to make energy. This energy is diverted to muscle and brain tissues, and certain cells of the immune system may become more active.
• Chronic stress response: Chronic stress occurs when a person has continuous acute stress responses. Chronic stress results in more sustained changes in the body, such as increased blood pressure, which over time can result in damaged arteries and heart disease. The continuous increase in stress hormones might also result in suppression of the immune system’s white blood cells, leading to an increased risk of infections.

Your Immune System's Reaction to Infections

Your body has an innate immune response, which is the first line of defense that provides an immediate and non-specific response to infectious pathogens (such as bacteria and viruses). Shortly afterwards, your body begins to generate its adaptive immune response, in which pathogens are specifically targeted and attacked by white blood cells.

• Acute stress: Researchers have found that during periods of acute stress, cells of the innate immune system are more active and increase their circulation throughout the body in order to patrol for infectious microbes.
• Chronic stress: During periods of chronic stress, the adaptive immune system is suppressed by high levels of stress hormones. As a result, your body might heal slower, could be less able to produce antibodies, and may be more susceptible to illness from infections.

Which Infections Are You More Likely to Get?

Studies have linked chronic stress with tuberculosis, herpes simplex virus reactivation, shingles, ulcers (caused by infectious Helicobacter pylori bacteria), and other infectious diseases.

Some studies of vaccinations have shown a decrease in effectiveness in individuals with high chronic stress. However, the size of the effect that stress really has on infection risk is not clear.

Common Cold: A classic study at Carnegie Mellon University, published in 1991, showed that the risk for the common cold was proportional to the degree of stress in a person’s life.

But stress due to a single, recent event can have a different effect than chronic stress. A subsequent study in 1998 showed that people who had chronic stress (due to life events, such as unemployment or interpersonal difficulties) for at least one month were more likely to get the common cold than those who had shorter durations of stress.

AIDS: The HIV virus leads to AIDS, a condition characterized by severe immunodeficiency. Stress doesn't lead to HIV infection, but stress can cause people who have been infected by the HIV virus to experience a quicker progression to AIDS. 

A UNC-Chapel Hill study published in 2000 found that men with HIV progressed to AIDS faster if they had chronic stress in their lives. For each increased stressful event, the risk for AIDS progression doubled.

Reducing Your Risk of Infections

See your doctor if you need help in coping with stress. There are numerous strategies recommended for coping with stress, including psychosocial interventions that decrease a person’s own perception of stress and improves their social supports. Certain medications may also help in reducing the stress that's caused by specific disorders.

How each person responds to stress varies. Some people deal with stress by engaging in unhealthy health behaviors, such as smoking, drinking, or excessive eating — all of which will contribute to the chances of getting infections. And in some cases, these health behaviors contribute to worse stress, resulting in a continuous cycle of poor health and stress. It is important to remember, though, that there are many factors involved in getting an infectious disease, and stress management should be accompanied by healthy habits, such as hand washing and avoiding exposure to infections.