Aubrey Bailey, PT, DPT, CHT  is a physical therapist with over 20 years of experience in a variety of healthcare settings.

Anita Chandrasekaran, MD, MPH, is board-certified in internal medicine and rheumatology and currently works as a rheumatologist at Hartford Healthcare Medical Group in Connecticut.

Rheumatoid arthritis (RA) is a condition that causes inflammation throughout the body. This condition occurs when your body's own immune system attacks healthy cells. RA often affects many different joints, including the knees, causing pain and difficulty with daily tasks.

This article discusses rheumatoid arthritis in the knees, including affected structures, symptoms, disease progression, and treatment.

Inflammation caused by rheumatoid arthritis attacks many different structures in your knees, such as the cartilage that provides padding between the bones, the ligaments that attach bone to bone, and the joint capsule that surrounds the entire joint. As RA progresses, it can also break down your bones.

Symptoms caused by RA in the knees are similar to other conditions that affect the knees, such as osteoarthritis. However, RA attacks joints on both sides of the body at the same time—a hallmark sign of this condition—while other conditions typically affect one side of the body.

In addition, stiffness caused by RA is worse in the mornings and improves with activity. With other conditions, joint mobility can get worse as the day goes on.

RA in the knee (and other joints) progresses through four stages.

In stage 1 of your condition, rheumatoid arthritis causes swelling in the knees and inflammation in the capsule that surrounds the joint. This leads to pain and stiffness.

In stage 2, inflammation causes damage to the cartilage that provides padding between the bones in your knee joints. You'll likely notice more stiffness and begin to lose some range of motion of your knees in this phase.

Stage 3 RA is considered severe. At this stage, inflammation continues to attack the soft tissues in your knees and now extends into your bones. Your mobility will be further impacted, and your bones might begin to shift out of place, causing your knees to look deformed.

In the final stage of RA, the inflammatory process is over. Function and mobility are significantly impacted, and your knees will continue to be swollen and very painful.

Rheumatoid arthritis affects the entire body. In addition to joint issues, RA symptoms often include:

RA is first diagnosed through a medical examination and blood tests. Symptoms of RA typically follow a certain pattern:

Blood tests for rheumatoid arthritis look for elevated levels of inflammation and specific markers that are common with autoimmune disorders. These tests include:

Imaging is used to assess the amount of damage RA has caused to your knees. X-rays show bone position and inflammation that is present in the joint. Magnetic resonance imaging (MRI) provides a picture of the soft tissues in your knees, such as cartilage and ligaments. Computed tomography (CT scan) can be used to provide more information about the extent of damage caused to your bones.

Rheumatoid arthritis in the knees is treated with medications, home remedies, and sometimes surgery.

Rheumatoid arthritis is commonly treated with medications that suppress your immune system to decrease excess inflammation in the body. However, these medications, called disease-modifying antirheumatic drugs (DMARDs), can take several months to show improvements.

Knee symptoms can also be treated with nonsteroidal anti-inflammatory drugs (NSAIDs), such as Aleve (naproxen) and Advil (ibuprofen). If these over-the-counter (OTC) medications aren't effective, your healthcare provider might prescribe short-term steroids.

Almost all patients with RA will need DMARD therapy. NSAIDs and steroids are only indicated for short-term use (less than three months) in the treatment of RA. Sometimes for the knee, intra-articular steroid injections are helpful for short-term treatment.

Home remedies can help decrease knee symptoms from RA when you're having a flare-up, including:

Over time, RA can cause knee damage that requires surgery. Knee arthroscopy uses a tiny camera and tools that are inserted through several tiny incisions. These tools are used to clean up frayed tissues and remove scar tissue to help decrease pain and improve mobility.

Severe RA can require total joint replacement surgery. Knee replacement surgery involves removing the damaged ends of your bones and replacing them with metal prostheses . After surgery, physical therapy is provided for six to eight weeks to help you regain movement and function.

Rheumatoid arthritis is a chronic inflammatory condition that causes your body to attack its own cells. RA commonly affects the joints, including the knees. RA is diagnosed with a medical exam, blood work, and imaging to assess the extent of your joint damage. Treatment includes medications, home remedies, and sometimes surgery.

Living with rheumatoid arthritis can be stressful. RA in the knees can make it difficult to walk, climb stairs, and stand for long periods of time. However, being proactive with your treatment can improve your quality of life. See a physical therapist for ideas on unloading your painful joints and maintaining your movement and strength. Talk to your healthcare provider about medication options.

RA causes pain that often increases with weight-bearing activities, such as walking or climbing stairs. You might also feel "locking" or "clicking" in your knees.

RA is diagnosed through a medical exam, blood work, and imaging to assess damage to your joints or internal organs.

Anti-inflammatory medications can decrease knee pain during an RA flare-up. Home remedies such as hot packs, gentle exercise, and the use of an assistive device (such as a cane) can also help.

Dealing with chronic inflammation? An anti-inflammatory diet can help. Our free recipe guide shows you the best foods to fight inflammation. Get yours today!

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Rheumatoid Arthritis Support Network. RA progression: What are the signs of rheumatoid arthritis progression?

American College of Rheumatology. Rheumatoid arthritis.

Rheumatoid Arthritis Support Network. RA diagnosis: What criteria are used to diagnose rheumatoid arthritis?

University of Washington Medicine. Knee surgery for rheumatoid arthritis.

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