Why does an area swells after a bump?

Question

What is the purpose? Is it to protect the wounded area?
Thank you.

Answer 1

When an injury occurs, small blood vessels (capillaries) leak fluid into the surrounding tissue. This increased blood flow then leads to inflammation: redness, warmth and swelling. The swelling causes pressure.

The purpose is to start the healing process in the injured area as the above process causes white blood cells and immune cells to rush to the area.