When Knee Pain May Mean Arthritis 

Learn about the various causes of knee pain, including different kinds of arthritis.

If you are experiencing pain, swelling and stiffness in the knees, you may have one of the following types of arthritis or related conditions. 


The most common form of arthritis, osteoarthritis  (OA) is caused by the breakdown of cartilage that cushions the ends of the bones where they meet to form joints. Without the protective layer, the bones to rub together, causing stiffness, pain and loss of joint movement in the joint. The knee is one of the joints most commonly affected by OA. In knee OA, you may feel a grating sensation when using the joint or a popping or crackling noise.

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease that causes the immune system to mistakenly attacks the joints. The result can be joint damage, pain, swelling, inflammation and loss of function. RA commonly affects joints on both sides of the body. If one knee is affected, the other knee is likely affected as well.

Juvenile Arthritis

Juvenile arthritis is the term used to describe types of arthritis that affect children age 16 years old or younger. There are several types of juvenile arthritis that cause knee pain and swelling.


Gout is a form of arthritis that occurs when too much uric acid (UA) can build up in the bloodstream. The acid turns into needle-like crystals in tissues of the body, including the joints. The first symptom of gout is intense pain and swelling in the big toe, but attacks may also commonly affect the knees. Symptoms include a rapid onset of severe pain, which usually reaches its peak after 4 to 12 hours. Lingering pain from gout attacks can persist for weeks, and later attacks tend to last longer and affect more joints.

Reactive Arthritis

Reactive arthritis is a chronic form of arthritis that often occurs following an infection of the genital, urinary or gastrointestinal system. Large joints are often affected, especially the shoulders, hips and knees.

Infectious Arthritis

Also called septic arthritis, this disease is caused by an infection within the joint. Infectious arthritis is often cause by bacteria that spread through the bloodstream to the joint. Sometimes it is caused by viruses or fungi. Knees are the most commonly affected joints in infectious arthritis.

Getting a Proper Diagnosis

Other common sources of knee pain include injuries such as tears, dislocations, sprains and or restrictive movement due to adhesions, or scar tissue. 

Arthritis is difficult to self-diagnose. Talk with your primary care doctor as soon as possible about your symptoms. You may be referred to a rheumatologist or orthopedist to get an accurate diagnosis so you can get the medical care you need. Left undiagnosed and untreated, your condition may worsen and cause disability.  

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