Inflammation: when the body's defense system turns harmful

Inflammation is part of the body's built-in defense and repair system. When you cut a finger or catch a cold, the redness, warmth and swelling that follow are signs that immune cells are rushing in to fight the threat and heal the damage. This short-lived, acute inflammation is essential for survival.

Chronic inflammation is different. Instead of switching off once the job is done, low-level inflammation can smolder quietly for months or years. You often cannot feel it, but over time it can damage healthy tissue and blood vessels throughout the body.

Researchers have linked this persistent inflammation to many of the leading causes of death and disability, including heart disease, stroke, diabetes, rheumatoid arthritis, asthma, dementia and several cancers. That is why inflammation gets so much attention in health news, and why doctors say it is worth taking seriously even when you feel well.

The encouraging news is that some of the most effective ways to calm unhealthy inflammation are routine habits rather than special treatments. Regular exercise sits at the top of the list. Moving every day, if possible, helps control appetite, lifts mood and improves sleep in the short term, and over the long term lowers the risk of heart disease, stroke, diabetes, dementia, depression and many cancers.

What you eat matters too. Meals built around vegetables, fruits, whole grains, beans, nuts, fish and olive oil are associated with lower levels of inflammatory markers, while heavily processed foods, sugary drinks and excess refined starch tend to push them up. Maintaining a healthy weight reduces the inflammatory signals produced by excess body fat.

Sleep and stress round out the picture. Poor or too little sleep raises inflammatory activity, and so does chronic psychological stress. Aiming for seven to nine hours of sleep, and using simple stress relief such as walking, breathing exercises or time with friends, all help keep inflammation in check.

Finally, do not smoke, and keep alcohol modest if you drink at all. If you live with a condition driven by inflammation, such as rheumatoid arthritis, work with your doctor on a treatment plan; many medicines can control symptoms and slow joint and organ damage. Everyday habits and good medical care work best together.