Knee Pain
Pain in or around the knee joint
Quick Facts
- Type: Joint and musculoskeletal symptom
- Common causes: Injury, overuse, arthritis
- Often affects: Athletes and older adults
- Many cases: Improve with rest and self-care
Overview
Knee pain is a very common complaint that can affect people of all ages. The knee is a large, complex joint made up of bones, cartilage, ligaments, and tendons, and a problem with any of these structures can cause pain. The discomfort may be located in the front, back, sides, or deep within the joint.
Knee pain ranges from a minor ache that goes away with rest to severe pain that limits walking and daily activities. It may come on suddenly after an injury or develop gradually from wear and tear. Many cases improve with simple self-care, but persistent, severe, or worsening knee pain deserves medical evaluation to find and treat the cause.
Common Causes
Knee pain has many possible causes, which can be grouped into a few categories.
- Injuries: Ligament tears (such as ACL injuries), meniscus tears, sprains, and fractures, often from sports or falls
- Overuse: Tendinitis, runner's knee (pain around the kneecap), and bursitis from repetitive stress
- Arthritis: Osteoarthritis from wear and tear, rheumatoid arthritis, and gout
- Kneecap problems: Pain or instability where the kneecap moves over the joint
- Referred pain: Sometimes hip or back problems cause pain felt in the knee
Associated Symptoms
Other symptoms that come with knee pain can help point to the cause and signal how serious it is.
- Swelling, warmth, or redness around the joint
- Stiffness or reduced range of motion
- A popping or grinding sensation
- The knee giving way, locking, or feeling unstable
- Difficulty fully straightening or bending the knee
- Fever along with a hot, swollen knee, which needs urgent attention
Diagnosis & Evaluation
Finding the cause of knee pain combines history, examination, and sometimes imaging.
- History: How the pain started, what makes it better or worse, and any injury or swelling.
- Physical examination: Checking movement, stability, tenderness, and swelling, and testing the ligaments and cartilage.
- Imaging: X-rays to look at bones and arthritis; MRI to see ligaments, cartilage, and soft tissue.
- Joint fluid analysis: Removing and testing fluid if infection, gout, or inflammation is suspected.
Treatment & Management
Treatment depends on the cause, but many cases respond to conservative care.
- Rest, ice, compression, and elevation (RICE): Helpful for many acute injuries and flare-ups.
- Pain relief: Over-the-counter pain relievers and anti-inflammatory medicine when appropriate.
- Physical therapy: Exercises to strengthen the muscles around the knee and improve flexibility and stability.
- Supports: Braces or supportive footwear to protect the joint.
- Injections: Such as corticosteroids for certain types of arthritis or inflammation.
- Surgery: Considered for serious injuries, advanced arthritis, or problems that do not improve with other treatment.
Maintaining a healthy weight and staying active within comfortable limits help protect the knees over the long term.
Self-Care & Prevention
Many causes of knee pain can be reduced with sensible habits:
- Maintain a healthy weight to ease load on the knees
- Strengthen the thigh and hip muscles that support the knee
- Warm up before exercise and increase activity gradually
- Wear supportive, well-fitting shoes
- Use proper technique in sports and lifting
- Rest and treat minor knee injuries promptly before they worsen
When to See a Doctor
See a doctor for knee pain that is severe, does not improve with rest, keeps returning, or limits your daily activities. Also seek evaluation if the knee is significantly swollen, unstable, or locks or gives way.
Seek urgent care if you cannot bear weight after an injury, the knee is visibly deformed, or it is hot, red, and swollen with a fever, which can signal an infected joint. Sudden calf swelling and pain with redness should also be checked promptly, as it can indicate a blood clot.
Frequently Asked Questions
What are the most common causes of knee pain?
Common causes include injuries such as ligament and meniscus tears, overuse problems like tendinitis and runner's knee, and arthritis from wear and tear. Less often, gout, infection, or referred pain from the hip or back are responsible.
When can I treat knee pain at home?
Mild knee pain from minor strains or overuse can often be managed with rest, ice, compression, elevation, and over-the-counter pain relievers. If the pain is severe, persists, or comes with significant swelling or instability, see a doctor.
What does it mean if my knee locks or gives way?
A knee that locks, catches, or gives way can suggest a cartilage (meniscus) or ligament problem. These symptoms should be evaluated, as they may need specific treatment and can affect knee stability.
How can I protect my knees?
Maintain a healthy weight, strengthen the muscles around the knee and hip, warm up before exercise, increase activity gradually, and wear supportive shoes. Treating minor injuries early also helps prevent ongoing problems.
When is knee pain an emergency?
Seek urgent care if you cannot bear weight after an injury, the knee looks deformed, or it is hot, red, and swollen with a fever, which can signal an infected joint. Sudden calf swelling, pain, and redness should also be checked promptly for a possible blood clot.
References
- American Academy of Orthopaedic Surgeons (OrthoInfo). Knee.
- Mayo Clinic. Knee pain.
- MedlinePlus, U.S. National Library of Medicine. Knee injuries and disorders.
- Arthritis Foundation. Knee Pain.