Why does my knee hurt?

From stiffness and instability to popping or crunching noises, the symptoms of knee pain can affect people differently, regardless of age. Additionally, the causes of this common condition can range from an injury, such as a torn ligament, to a medical issue, including arthritis. In some cases, knee pain can develop gradually due to overuse, poor movement mechanics, or the natural wear and tear that occurs as the body ages.

“Not all knee pain is serious or requires medical attention,” explains Dr. Joel Smith, an orthopedic surgeon affiliated with Sharp HealthCare. “You should see your doctor when you find yourself unable to put weight on your knee, notice pain or swelling that limits normal activity, or have a fever in addition to knee pain and swelling.”

3 common causes of knee pain

The most common knee injuries associated with knee pain are ligament injuries, cartilage tears and arthritis of the knee. Repetitive stress from daily activities, exercise or work-related movements can also irritate the knee joint over time, especially when muscles that support the knee are weak or tight.

Ligament injuries — There are four main ligaments that help the knee function properly. A ligament tear directly affects the ability to participate in normal activities, such as walking and exercising. Not all knee ligament injuries are the same or require the same treatment.

Cartilage tears — Cartilage is a type of tissue that is strong like a bone but flexible like a ligament. It is found on either side of the knee joint. Torn cartilage is a common injury and is associated with the “popping” noise some people may experience. Surgery is often required for this kind of tear.

Arthritis — There are many different kinds of arthritis that can be associated with stiffness and swelling of the knee.

Knee pain risk factors

While some causes of knee pain — such as certain types of arthritis — are genetic, there are risk factors that can increase a person’s overall chance of experiencing knee problems. These factors include being overweight; a lack of strength; playing certain sports, including basketball and soccer; or a previous injury.

“Not all types of knee pain are preventable, but there are ways to reduce the discomfort and disability of living with this issue,” says Dr. Smith. “To prevent knee pain or the development of certain knee injuries, I always tell my patients to maintain a healthy weight, exercise regularly at a level that is comfortable for them, and stay flexible through balance and stability training.”

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