Knee Pain: Causes, Symptoms, and Treatment

Knee pain is a common complaint that affects people of all ages. It can have numerous causes, including injuries like torn ligaments or cartilage damage. Medical conditions such as arthritis, gout, and infections can also lead to knee pain.

Many types of mild knee pain respond well to self-care measures, such as physical therapy and wearing knee braces, which can help alleviate discomfort. However, in some cases, surgical repair of the knee may be necessary.

Symptoms of Knee Pain

The location and severity of knee pain can vary depending on the cause. Common symptoms associated with knee pain include:

• Swelling and stiffness
• Redness and warmth to the touch
• Weakness and instability
• Popping or crunching sounds
• Inability to fully straighten the knee

When to See a Doctor

Contact your doctor if you:

• Cannot bear weight on your knee or feel the knee is unstable or giving out
• Notice significant swelling
• Are unable to fully extend or bend your knee
• See an obvious deformity in your knee
• Have a fever along with redness, pain, and swelling in your knee
• Experience severe pain due to an injury

Causes of Knee Pain

Knee pain can result from injuries, mechanical issues, arthritis, and other problems.

Knee Injuries

Knee injuries can affect ligaments, tendons, bones, and cartilage within the knee joint. Common knee injuries include:

• Anterior Cruciate Ligament (ACL) Injury

  ACL injuries often occur during sports involving sudden changes in direction, such as soccer, basketball, and hockey. The ACL is one of four ligaments connecting the shinbone to the thighbone, providing knee stability.

• Fractures

  Knee bones can fracture due to traumatic impacts, such as falls or car accidents. In people with osteoporosis, fractures can occur even with minor missteps.

• Meniscus Tear

  The meniscus is a crescent-shaped cartilage acting as a shock absorber. It can tear during sports involving twisting motions of the knee.

• Bursitis

  This inflammation of the knee’s bursa (a fluid-filled sac reducing friction) often occurs in people who kneel frequently, like carpet layers or wrestlers.

• Patellar Tendinitis (Jumper’s Knee)

  Overuse of the patellar tendon, connecting the kneecap to the shinbone, can lead to irritation and pain, especially in sports involving frequent jumping.

Mechanical Issues

Mechanical problems causing knee pain include:

• Loose Body (Joint Mouse)

  Pieces of bone or cartilage floating in the joint can cause pain if they get stuck.

• Iliotibial Band Syndrome

  Irritation of the tissue running along the outside of the thigh to the knee, often affecting runners and cyclists.

• Dislocated Kneecap (Patellar Luxation)

  The kneecap slips out of place, often to the outer side of the knee.

• Compensatory Pain

  Altered walking patterns due to hip or foot pain can stress the knee.

Types of Knee Arthritis

There are over 100 types of arthritis, with the following commonly affecting the knee:

• Osteoarthritis

  A wear-and-tear condition where cartilage deteriorates over time.

• Rheumatoid Arthritis

  An autoimmune disease causing joint inflammation and damage.

• Gout

  A form of arthritis caused by high levels of uric acid leading to painful joint inflammation.

• Septic Arthritis

  Infection in the joint, requiring urgent medical treatment to prevent cartilage damage.

Other Knee Issues

Patellofemoral Pain Syndrome refers to pain between the kneecap and thighbone, often affecting athletes and young adults with poorly aligned kneecaps.

Risk Factors

Factors increasing the risk of knee pain include:

• Excess Weight

  Adds stress to knee joints, accelerating cartilage wear.

• Muscle Weakness or Inflexibility

  Strong muscles support knee stability.

• Sports or Occupations

  Activities like skiing, basketball, or construction work strain the knees.

• Previous Injuries

  Increase susceptibility to future knee problems.

Prevention

While not all knee pain can be prevented, steps like strengthening muscles around the knee and using braces during sports can reduce the risk of injury. Wearing braces does not weaken muscles.