A sprain occurs when ligaments are suddenly overstretched or in worse cases, the ligaments could even be torn. Since it is concerned with the ligament, sprains occur in joints. There are four degrees of sprain:

    1st degree - a minor tear or stretch of a ligament.
    2nd degree - a tear of a ligament, which is usually followed by pain or swelling.
    3rd degree - a complete rupture.
    4th degree - the most severe and actually breaks the ligament, along with some small bones if severe enough, and requires surgery to repair.

Sprains are usually experienced in the ankle and the probably most popular cause of sprain is playing sports like basketball, volleyball, football and running. The best way to prevent sprain is to use proper gear, such as ankle guards, when engaging in sports.