Nodules are lumps that people with rheumatoid arthritis develop under their skin or in other areas. They’re often harmless, but sometimes they can cause pain or other complications.

Rheumatoid arthritis (RA) is an autoimmune condition that happens when your body’s immune system attacks the joint lining known as the synovium. The condition can cause firm lumps called nodules to develop on various parts of the body, such as the:

  • hands
  • feet
  • wrists
  • elbows
  • ankles
  • lungs

Read on to discover how these nodules form as well as treatments.

Doctors don’t know exactly why rheumatoid nodules form. Typically, a person gets rheumatoid nodules when they’ve had RA for several years. The nodules are composed of the following components:

  • Fibrin. This protein plays a role in blood clotting and can result from tissue damage.
  • Inflammatory cells. Rheumatoid arthritis can cause inflammation in the body, leading to the development of nodules.
  • Dead skin cells. Dead skin cells from proteins in the body can build up in the nodules.

The nodules can closely resemble other conditions, like epidermoid cysts and tophi caused by gout. On your elbow, a condition called olecranon bursitis can cause a painful lump. But the signs and symptoms of bursitis are usually different from nodules.

Rheumatoid nodules can form in areas including the:

  • backs of your heels
  • bony outer points of your elbows
  • fingers
  • knuckles

These areas are usually where pressure is placed on your body’s surfaces.

In rare cases, the nodules can form in other areas, like your lungs or vocal cords.

Although they might sound serious, rheumatoid nodules in the lungs are usually harmless and don’t cause symptoms. Typically, no treatment is required. But imaging tests may be needed to rule out other lung conditions.

If a person’s movement is limited and they need to stay in bed for long periods, they may develop rheumatoid nodules in areas such as the:

  • hips
  • legs
  • base of the spine (sacrum)
  • back of the head

Rheumatoid nodules can range from very small (around 2 millimeters) to larger (around 5 centimeters). They’re usually round in shape, though they may have irregular borders.

The nodules feel firm to the touch and usually move when pressed. Sometimes the nodules can form a connection with tissues or tendons underneath the skin and may not move when pressed.

Nodules usually don’t hurt. But they sometimes are tender to the touch. This usually occurs when a person is experiencing a RA flare-up.

Very large nodules or nodules on certain areas can press on nearby nerves. This can cause discomfort and affect a person’s ability to move their hands, feet, and more.

Nodules vary in size, shape, and location on the body. Sometimes a person may have one nodule. Other times they may have a collection of smaller nodules.

Several factors may put you more at risk for developing nodules. These include:

  • RA severity. Usually, the more severe a person’s RA, the more likely they’ll have nodules.
  • Rheumatoid factor (RF) antibody. People with nodules typically have RF antibodies in their blood. A doctor can check your RF level using a blood test.
  • Anti-CCP antibody. This is another factor that is detected with a blood test. People with nodules usually have an antibody called anti-CCP in their blood.
  • Smoking. People who smoke may be more likely to develop nodules.
  • Other RA complications. Nodules are more common in people who have other complications of RA, such as lung disease and vasculitis.

Accelerated nodulosis

Some evidence suggests that a common rheumatoid arthritis medication, methotrexate, may cause nodules to develop in some people. Doctors call this condition accelerated nodulosis.

Accelerated nodulosis is associated with small nodules that appear quickly. They tend to show up in groups on your hands, feet, or ears. If the nodules are problematic, your doctor may want to adjust the medications in your treatment plan.

For some people with RA, nodules may go away. But they may also increase in size instead. It’s impossible to predict how nodules will change over time.

If a nodule is causing problems, your doctor can treat it to make it smaller or remove it.

Rheumatoid nodules don’t always require treatment. But if they cause pain or restrict movement, your doctor may recommend treatments.

Taking disease-modifying antirheumatic drugs (DMARDs) may help reduce the size of some rheumatoid nodules.

When necessary, a small dose of injectable corticosteroid medication can be used to shrink problematic nodules.

Surgery is also an option to remove them. In rare cases, your doctor may recommend surgery if a nodule is causing complications. But nodules often come back after they’ve been removed.

Many natural remedies for RA claim to relieve pain and other symptoms of the condition. According to the National Center for Complementary and Integrative Health, many of these treatments are safe to try, even if their effects are not proven.

But you should know that no natural therapies have been shown to help with rheumatoid nodules.

If you want to try alternative therapies, it’s always best to talk with your doctor first to ensure they’re right for you.

Be especially cautious about herbs or dietary supplements for arthritis. They can have severe side effects. The Food and Drug Administration (FDA) has also warned that some over-the-counter (OTC) products for arthritis pain are contaminated with prescription medications.

If you’re getting nodules on pressure points like your elbow, reducing irritation and pressure on those points could help. You might need to change some of your day-to-day activities or use padding to reduce pressure. Talk with your doctor to see if this at-home strategy can help you.

You may be wondering whether rheumatoid nodules are dangerous. Generally, the answer is no. But if they cause complications, you’ll need to get medical care. The most common complications are painful or infected nodules.

The skin over the nodules can become irritated or infected on areas of greater pressure, like your feet. The result can be redness, swelling, and warmth at the nodules.

Infected nodules require medical attention. Antibiotics may be required to treat a nodule infection.

See your doctor if you have severe or worsening pain in any nodules you might have or if the nodules are affecting your ability to move.

Nodules on the bottom of the feet may also make walking difficult, cause gait abnormalities, or shift stress to other joints, leading to knee, hip, or low back pain.

Rheumatoid nodules can range from annoying to painful. While they don’t usually require treatment, talk with your doctor if you notice pain or infection or have difficulty with mobility.