Stress

6 min read · Reviewed June 2026

Stress is the body's response to a demand or challenge. In short bursts it can be helpful — sharpening focus before a deadline or a race. The problem is chronic stress: when the pressure never lets up, the same response that protects you in an emergency starts to wear the body down.

What happens in the body

When your brain senses a threat, the Mayo Clinic explains, the hypothalamus signals the adrenal glands to release adrenaline and cortisol. Heart rate and blood pressure rise, energy is mobilized, and non-urgent systems like digestion are dialed down. This is the "fight-or-flight" response.

Normally this system is self-limiting: once the threat passes, hormone levels fall and the body returns to baseline. Trouble starts when stressors are constant and the response stays switched on.

When stress becomes chronic

The American Psychological Association notes that stress affects nearly every system in the body — musculoskeletal, respiratory, cardiovascular, endocrine, gastrointestinal, nervous, and reproductive. The body handles stress well in small doses, but long-term activation takes a toll.

Over time, research links chronic stress to higher blood pressure and cardiovascular strain, and it can contribute to anxiety and depression. Recognizing stress early — and building in recovery — is part of protecting your physical health, not just your mood.

What helps

Regular movement, consistent sleep, social connection, and relaxation practices (such as slow breathing) all help the body return to baseline. So does identifying your specific stressors and reducing or reshaping the ones you can control.

Key points

Short-term stress can be useful; chronic, unrelenting stress is what harms health.
The fight-or-flight response (adrenaline + cortisol) is normally self-limiting.
Chronic stress affects nearly every body system and is linked to heart disease, anxiety, and depression.
Movement, sleep, connection, relaxation, and reducing controllable stressors all help.