Causes of Knee Pain in Adults

Causes of Knee Pain in Adults range from acute injuries to chronic conditions. Here are some common causes explained:

1. Injuries

• Ligament Injuries: Damage to ligaments, such as the ACL (anterior cruciate ligament), PCL (posterior cruciate ligament), MCL (medial collateral ligament), or LCL (lateral collateral ligament), often due to sports or trauma.
• Meniscus Tears: The meniscus is a cartilage that acts as a shock absorber in the knee. Tears can occur from twisting or overuse.
• Fractures: Breaks in the bones of the knee, such as the patella (kneecap), can cause severe pain.
• Tendon Tears: The patellar tendon or quadriceps tendon can tear, often due to overuse or sudden force.

2. Overuse or Repetitive Strain

• Patellar Tendinitis (Jumper’s Knee): Inflammation of the patellar tendon, common in athletes who jump or run frequently.
• Iliotibial Band Syndrome (ITBS): Pain on the outer side of the knee caused by friction of the IT band over the lateral femoral epicondyle, often seen in runners.
• Bursitis: Inflammation of the bursae (small fluid-filled sacs that cushion the knee joint), often due to repetitive kneeling or overuse.

3. Degenerative Conditions

• Osteoarthritis: Wear and tear of the cartilage in the knee joint, leading to pain, stiffness, and swelling. Common in older adults.
• Rheumatoid Arthritis: An autoimmune condition that causes inflammation of the joint lining, leading to pain and swelling.

4. Mechanical Issues

• Patellofemoral Pain Syndrome (Runner’s Knee): Pain around or behind the kneecap, often due to misalignment or overuse.
• Dislocated Kneecap: When the patella slips out of place, causing pain and swelling.
• Loose Bodies: Fragments of bone or cartilage that float in the joint space, causing pain and locking.

5. Infections and Inflammatory Conditions

• Septic Arthritis: A bacterial infection in the knee joint, causing severe pain, swelling, and fever.
• Gout: A type of arthritis caused by the buildup of uric acid crystals in the joint, leading to sudden, severe pain and swelling.
• Pseudogout: Similar to gout but caused by calcium pyrophosphate crystals.

6. Other Causes

• Obesity: Excess weight puts additional stress on the knee joint, leading to pain and degeneration.
• Referred Pain: Pain originating from other areas, such as the hip or lower back, can sometimes be felt in the knee.
• Nerve Compression: Conditions like sciatica can cause pain that radiates to the knee.

Symptoms to Watch For:

• Swelling or stiffness
• Redness or warmth
• Popping or crunching noises
• Inability to fully straighten or bend the knee
• Instability or weakness

When to See a Doctor:

• Severe pain or swelling
• Inability to bear weight on the knee
• Visible deformity
• Signs of infection (fever, redness, warmth)

Proper diagnosis and treatment are essential for managing knee pain effectively. This may include rest, physical therapy, medications, or in some cases, surgery. Always consult a healthcare professional for persistent or severe knee pain.