Knee pain
Causes of knee pain
Knee pain is a common problem that can affect people of all ages and activity levels. Because the knee is a complex joint that supports much of the body’s weight, it’s especially vulnerable to injury, wear and tear and medical conditions. Understanding the possible causes of knee pain can help guide proper care and treatment.
How the knee works
The knee joint connects the thigh bone (femur) to the shin bone (tibia) and includes cartilage, ligaments, tendons and muscles that work together to allow movement and provide stability. Pain can develop when any of these structures are injured, irritated or damaged.
Common causes of knee pain
1. Injuries
Knee injuries are a frequent cause of pain, especially in active individuals. These may occur suddenly or develop over time.
- Ligament injuries such as ACL or MCL tears
- Meniscus tears
- Tendon injuries
- Knee fractures
- Dislocations
Injuries often cause sudden pain, swelling and difficulty moving the knee.
2. Arthritis
Arthritis is one of the most common causes of ongoing knee pain.
- Osteoarthritis occurs when cartilage wears down over time
- Rheumatoid arthritis is an autoimmune condition causing joint inflammation
- Post-traumatic arthritis develops after a previous knee injury
Arthritis-related knee pain is often accompanied by stiffness, swelling and reduced mobility.
3. Overuse and repetitive stress
Repeated movements or excessive strain on the knee can lead to irritation and pain over time.
- Runner’s knee
- Jumper’s knee
- Tendinitis
- Bursitis
These conditions are common in athletes and individuals with physically demanding jobs.
4. Poor alignment or biomechanics
Problems with posture, walking patterns or joint alignment can place extra stress on the knee.
- Flat feet or high arches
- Muscle imbalances
- Hip or ankle issues affecting knee movement
- Improper footwear
These factors can contribute to chronic knee discomfort if left unaddressed.
5. Excess body weight
Carrying extra weight increases the load placed on the knee joints. Even small increases in body weight can significantly raise the stress on the knees, increasing the risk of pain and joint damage over time.
6. Inflammatory conditions
Some medical conditions cause inflammation that affects the knee joint.
- Gout
- Lupus
- Inflammatory arthritis
- Infections in or around the knee joint
These conditions may cause redness, warmth, swelling and severe pain.
7. Age-related changes
As people age, cartilage naturally becomes thinner and less flexible. Muscles may weaken and joints may become stiffer, making knee pain more likely even without a specific injury.
When to seek medical care
You should consider seeing a healthcare professional if knee pain:
- Persists for more than a few days
- Is severe or worsening
- Limits walking or daily activities
- Is accompanied by swelling, redness or warmth
- Follows a fall or injury
Early evaluation can help prevent further damage and guide effective treatment.
Managing knee pain
Treatment depends on the underlying cause and may include rest, physical therapy, medication, lifestyle changes or medical procedures. A proper diagnosis is key to choosing the right approach.