A fracture is a break or crack in a bone that can be caused by an accident, fall, or blow. Symptoms include a snapping sound as bone breaks, bone protruding from skin, detectable deformity of bone, abnormal movement of bone, grating sensation during movement, pain and tenderness, difficulty in moving or using the affected part, swelling, and discoloration.

A sprain refers to stretched or torn tendons, ligaments, and blood vessels around a joint and can be caused by an accident, fall, or blow. Symptoms of a sprain include pain, tender­ness, swelling, and discoloration in the joint area.

A muscle strain refers to stretched or torn muscle. It can be caused by excessive physical effort or improper posture during activity. Symptoms include pain, stiffness, and possibly swelling in the affected area.
It is sometimes difficult to tell the difference between a fracture and a sprain or strain until an X-ray has been performed. If you cannot tell, treat it as a fracture.