The usual signs and symptoms include pain, swelling, bruising, instability, and loss of the ability to move and use the joint (called functional ability). However, these signs and symptoms can vary in intensity, depending on the severity of the sprain. Sometimes people feel a pop or tear when the injury happens.
Doctors closely observe an injured site and ask questions to obtain information to diagnose the severity of a sprain. In general, a grade I or mild sprain is caused by overstretching or slight tearing of the ligaments with no joint instability. A person with a mild sprain usually experiences minimal pain, swelling, and little or no loss of functional ability. Bruising is absent or slight, and the person is usually able to put weight on the affected joint.
A grade II or moderate sprain is caused by further, but still incomplete, tearing of the ligament and is characterized by bruising, moderate pain, and swelling. A person with a moderate sprain usually has more difficulty putting weight on the affected joint and experiences some loss of function. An x ray may be needed to help the health care provider determine if a fracture is causing the pain and swelling. Magnetic resonance imaging is occasionally used to help differentiate between a significant partial injury and a complete tear in a ligament, or can be recommended to rule out other injuries.
People who sustain a grade III or severe sprain completely tear or rupture a ligament. Pain, swelling, and bruising are usually severe, and the patient is unable to put weight on the joint. An x ray is usually taken to rule out a broken bone. When diagnosing any sprain, the health care provider will ask the patient to explain how the injury happened. He or she will examine the affected area and check its stability and its ability to move and bear weight.
Typically, people with a strain experience pain, limited motion, muscle spasms, and possibly muscle weakness. They can also have localized swelling, cramping, or inflammation and, with a minor or moderate strain, usually some loss of muscle function. Patients typically have pain in the injured area and general weakness of the muscle when they attempt to move it. Severe strains that partially or completely tear the muscle or tendon are often very painful and disabling.Click here for more infomation on sprains and strains at the National Institute of Health website >
National Institute of Arthritis and Musculoskeletal and Skin Disease (NIAMS)
National Institutes of Health