Knee pain is a common complaint amongst people of all ages: as the largest joint in the body, connected to three major bones (femur, tibia, and fibula), and surrounded by many discs, ligaments, tendons, and muscles, the knee receives a lot of wear and tear. Knee pain may result from this daily wear, overuse, injury, old age, or an underlying medical condition.
The most common cause of knee pain is an injury from a blow, a fall, or an irregular twisting of the knee. An unfortunate twist or fall may result in a tear, strain, or sprain to the ligaments surrounding the knee, such as the anterior cruciate ligament (ACL), or to the meniscus, the cartilage which cushions the knee joint. A forceful blow or fall may result in a fracture (minor break) of the kneecap, or in a dislocation, in which the kneecap slips out of place. In rare cases of excessive force, the knee joint may become dislocated, in which case immediate medical attention is required. Sudden injuries to the tendons, ligaments, and bones of the knee are common among those who play sports and may result in bruising, swelling, numbness or a tingling sensation in the knee or the area below it.
Injuries to the knee can also occur from overuse: repetitive or prolonged activities such as running and cycling, as well as obesity, can place excess pressure on the knee. Common overuse injuries include tendinitis (inflammation to one or more tendons, the tissue that connects muscle to bone), knee bursitis (inflammation of the fluid sacs, or bursa, which cushion the knee joint), and iliotibial band syndrome (tightening of the ligament that runs along the outer thigh).
Other medical conditions that may cause knee pain include degenerative diseases such as osteoarthritis, rheumatoid arthritis, or gout (which affect the knee joint), cysts, or an infection in the joint, skin, or bursa around the knee. Injuries elsewhere in the body, such as a pinched nerve or damage to another joint that leads to overcompensation in the knee may also result in knee pain, swelling, or stiffness.
Treatment depends on the location and severity of the knee pain. Many knee problems respond well to home treatment such as icing and elevation to reduce swelling and inflammation, rest in order to reduce strain from repetitive stress, and over-the-counter medications to relieve pain. Chronic conditions and severe injuries should be consulted and treated by a medical professional and may require treatments such as physical therapy, prescription medication, or surgery.