Sprains affect your joints. Strains affect your muscles. Both usually occur after a fall or sudden movement that violently pulls or twists a part of your body. Chronic overuse of muscles or joints can also cause strains and sprains.
Symptoms of a sprain:
Pain in the affected joint
Rapid swelling of a joint, often accompanied by bruising
Stiffness and difficulty moving a joint
Increase in skin temperature near the swelling, and redness of the skin
Symptoms of a