When inflammation turns from helper to hazard

Inflammation is your body's built-in healing response. When it fails to switch off as it should, it can flip from helpful to harmful. That long-running, chronic inflammation can quietly injure tissues and organs, causing fatigue, joint pain, and digestive trouble - and raising the risk of serious illnesses like heart disease, stroke, and cancer. Here is how it starts and what to watch for.

What drives chronic inflammation

Chronic inflammation usually begins when the body's natural reaction to a problem - an infection or an injury - does not shut down properly. Several routes can lead there. In one, the original threat never fully clears: the body cannot rid itself of the offending substance, whether that is an infectious organism, an irritant, or a chemical toxin. The immune system is good at eliminating invaders, but some pathogens withstand even our strongest defenses, hiding in tissues and provoking the inflammatory response again and again.

Another route: the immune system enters "threat mode" with no real threat present. In autoimmune disorders it seems to become oversensitised to the body's own healthy cells, attacking joints, intestines, or other organs as though they were dangerous. As the response grinds on, it damages the body rather than healing it.

Unhealthy lifestyle choices can also keep inflammation smouldering. Smoking, inactivity, and a diet heavy in processed foods and refined carbohydrates all feed chronic inflammation - and that, in turn, raises the risk of many diseases, among them heart disease, stroke, diabetes, cancer, and chronic obstructive pulmonary disease.

Signs and symptoms of chronic inflammation

The markers of chronic inflammation are far subtler than those of the acute kind. There is no sharp sting as with a cut, no visible swelling or redness to alert you. It can be body-wide or confined to particular areas. Symptoms linked to chronic inflammation include:

Fatigue and low energy

Depression and anxiety

Muscle aches and joint pain

Constipation, diarrhea, and other gut complaints

Shifts in weight or appetite

Headaches

A "fuzzy" mental state often called brain fog.