Inflammation is your body's way of protecting and healing itself when something goes wrong. When you get a splinter, scrape your knee, or catch a cold, the injured or infected area often becomes red, warm, swollen, and sore. That's inflammation at work.

Here's what's happening: your body sends extra blood and special cells to the problem area, like dispatching emergency crews to an accident. The redness and warmth come from increased blood flow. The swelling happens because fluid builds up as your body fights infection or repairs damage. The soreness is your body's way of telling you to be careful with that area while it heals.

Inflammation usually helps you recover. A sore throat can be inflammation fighting the germs making you sick. A sprained ankle swells up as your body rushes to repair torn tissue. Sometimes inflammation becomes a problem itself, though. Conditions like arthritis involve inflammation that doesn't turn off properly, causing ongoing pain and swelling in joints.

When doctors describe tissue as inflamed, they mean it's showing these telltale signs of your body's repair system in action.