IRIS: A concern for people
starting HIV therapy

April 2008     View PDF     En español

What is inflammation?

Inflammation means to put on fire, and it’s a complex response that results when your body attacks germs or repairs damaged tissue. A simple example of it is the redness, swelling and soreness that emerges around a cut as it’s healing. For your immune system to repair the damage and clear any infection that’s present, cells and fluids are recruited to the site of the damage. This shows up as swelling, redness and pain.

Inflammation can appear nearly anywhere in your body. It can occur in an organ like the liver, in lymph nodes, in nerve fibers, and even in areas outside organs like your immune system. Inflammation can be acute or chronic.

Acute inflammation is when your body first responds by sending white blood cells to the damaged area. Your circulatory and immune systems assist in the process. For the most part, acute inflammation is normal and healthy.

By contrast, chronic inflammation persists over time. In this case, your body shifts the types of cells that are present. This causes a situation where cells and tissues are healed and destroyed at the same time. While it’s not well understood, chronic inflammation is thought to be unhealthy and possibly linked to a number of serious diseases including heart disease and Alzheimer’s.