Chronic stress has what effect on the immune system?

• A. It suppresses certain immune functions and alters cytokine balance, increasing infection risk and slowing wound healing.
• B. It enhances immune function across all systems.
• C. It has no effect on the immune system.
• D. It only affects the endocrine system.

Answer: (A)

Chronic stress keeps the body's stress-response systems active over a long period, with hormones like cortisol and catecholamines shaping how the immune system works. This sustained hormonal environment tends to dampen immune cell activity—think of reduced T-cell function and lower natural killer cell activity—and it shifts cytokine signals in a way that can undermine the body’s ability to fight infections and coordinate healing. Because of that, people under chronic stress often have a higher risk of infections and slower wound healing. The best answer reflects both the suppression of certain immune functions and the altered cytokine balance, along with the real-world consequences of increased infection risk and delayed healing. Other statements—claiming universal immune enhancement, no effect, or effects limited to the endocrine system—don’t fit the evidence, since chronic stress clearly affects immune processes and clinical outcomes as well.