Know the basics
What is knee swelling?
Knee swelling, sometimes called an “effusion,” refers to swelling within the knee joint. An effusion can be caused by many different things, including injuries to the ligaments, cartilage, bones, or surrounding structures. Swelling can occur within the knee joint (effusion) or on the outside of the knee joint (bursitis), and can occur suddenly as a result of an injury or slowly as a result of overuse injuries.
How common is knee swelling?
Knee swelling is common. It can affect any patients at any age. It can be managed by reducing your risk factors. Please discuss with your doctor for further information.
Know the symptoms
What are the symptoms of knee swelling?
Symptoms depend on the cause and they range from mild to severe swelling. Pain, tenderness, redness, fever, and chills can also occur. Knees can have bruises or become stiff so that walking is hard. There may be some signs or symptoms not listed above. If you have any concerns about a symptom, please consult your doctor.
When should I see my doctor?
You should contact your doctor if you have any of the following:
- If you see signs of infection (fever, redness, warmth).
- If your knee, lower leg, or foot becomes pale, cool, or
- If you don’t get better with
- If you have severe pain or cannot put weight on your knee.
- If your leg gets numb, weak, or tingles.
If you have any signs or symptoms listed above or have any questions, please consult with your doctor. Everyone’s body acts differently. It is always best to discuss with your doctor what is best for your situation.
Know the causes
What causes knee swelling?
The many causes of effusions include injuries such as tears of the anterior cruciate (ACL), posterior cruciate (PCL), and medial and lateral collateral (MCL, LCL) ligaments.
Tearing of the meniscus (knee cartilage), fractures of the bones of the knee joint, or injuries to the cartilage lining the inside of the bones (articular cartilage) can also cause knee effusions.
Bursitis, tendinitis, strains, and sprains are causes of swelling outside the knee joint.
Forceful injuries, such as blows during contact sports or falls, can cause fluid or blood to build up within the knee.
Broken bones, arthritis, gout, cysts, dislocated kneecaps, infections, tumors, and aging-related degeneration are other causes.
Sudden turning, stopping, moving from side to side, and awkward landings can lead to knee stress or overuse.
Know the risk factors
What increases my risk for knee swelling?
There are many risk factors for knee swelling, such as:
- Your likelihood of developing a swollen knee related to arthritis increases as you age.
- People who participate in sports that involve twisting the knee, such as basketball, are more likely to experience the types of knee injuries that cause swelling.
- Excess weight puts added stress on the knee joint, contributing to the tissue and joint overload and knee degeneration that can lead to a swollen knee. Obesity increases your risk of osteoarthritis, one of the more frequent causes of knee swelling.
Understand the diagnosis & treatment
The information provided is not a substitute for any medical advice. ALWAYS consult with your doctor for more information.
How is knee swelling diagnosed?
The doctor makes a diagnosis from the medical history, physical examination, and additional tests as indicated. The doctor will ask questions about the nature of the swelling, how quickly it occurred, and if there was an injury, how it happened. In addition, answering questions about what kind of exercises and activities have been performed, as well as previous injuries may be important.
X-rays are often useful in evaluating knee swelling, and additional tests such as computed tomography (CT), magnetic resonance imaging (MRI), and arthrocentesis may help determine the cause of knee swelling. In arthrocentesis, the doctor puts a needle into the knee joint using sterile technique and removes fluid. This fluid is sent to a laboratory for study to determine what is causing the fluid to accumulate.
How is knee swelling treated?
Treatment goals are to determine what is causing the swelling, decrease the swelling, and allow for return to activities as soon and safely as possible. Self-care often works well, but any underlying conditions (such as rheumatoid arthritis or gout) must be treated.
After injuries, the first 48 hours are most important. Use PRICE: protection, rest, ice, compression, and elevation. Resting and avoiding activities that may have started the problem (such as high-impact running, skiing, or playing tennis) are critical.
Using ice packs, an elastic bandage around the knee, pillows under the knee, cane or crutches, and special stretching and strengthening exercises often help. Rehabilitative exercises to restore range of motion and strength are useful once a diagnosis is determined.
Nonsteroidal anti-inflammatory drugs (NSAIDs) (ibuprofen, naproxen) and acetaminophen may relieve pain. Other treatments depend on the underlying condition and can include orthotics, braces, other medications, and surgery if indicated. Arthrocentesis is a short-term treatment for alleviating pain due to swelling, but the swelling can recur, and this procedure can cause infection in the joint if not performed properly.
Lifestyle changes & home remedies
What are some lifestyle changes or home remedies that can help me manage knee swelling?
The following lifestyles and home remedies might help you cope with knee swelling:
- Stop the activity causing the swelling until your doctor says you can start again.
- Make sure that you use the right sports technique and equipment, such as shoes and knee pads.
- Warm-up exercises, such as light aerobic exercise, correctly.
- Maintain a healthy weight.
- Stretch before and after sports or exercising, especially quadriceps and hamstring muscles.
If you have any questions, please consult with your doctor to better understand the best solution for you.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Ferri, Fred. Ferri’s Netter Patient Advisor.Philadelphia, PA: Saunders / Elsevier, 2012. Download version.
Swollen knee. http://www.mayoclinic.org/diseases-conditions/swollen-knee/basics/definition/con-20026072. Accessed September 22, 2015.
Review Date: January 4, 2017 | Last Modified: January 4, 2017