Why Do The Knee And Ankle Swell Up If Injured?

When an injury in the knee or ankle occurs, the normal cells in the region multiply to provide extra cushion to the affected area.  This is what actually causes the knee or ankle to appear swollen.  This sudden increase in cells and the resulting swelling is termed as hyperplasia.  In addition to that, there is a little internal bleeding as a direct result of the injury.

With regards to swelling, there are two different types of the state, namely false tumours and true tumours.  The first category is inclusive of inflammatory swellings includes injuries like bruises, fractures, sprains, black eyes, infectious swellings such as boils and abscesses.  

As for true tumours, these are the swellings that are developed from masses of tissues developing from already existing body cells.  Their growth does not cease and instead continues.  It is even true that some of these second-type tumours are benign and bring no real harm to the body.

Your knee and ankle swell up if in injured because the blood move to the injured area to try to heal it.