Three ways stress can make you sick

Stress is the body’s response to a perceived threat or challenge. In short bursts it is useful. Sustained, it becomes a health problem in its own right.

First, it suppresses immune function. Prolonged cortisol exposure reduces the body’s ability to fight infection, which is why stressful periods and repeated illness often arrive together.

Second, it disrupts sleep architecture. Even when total hours look normal, stress reduces deep and REM sleep, which is where physical repair and emotional processing happen.

Third, it changes behaviour. Under load, people eat differently, move less, and drink more. The physical consequences of stress often arrive through these choices rather than directly.

This article is general information, not medical advice, and it does not replace an assessment by a clinician who knows your history. If you are in immediate danger, call 911. For free 24/7 crisis support in the US, call or text 988.