Rheumatoid arthritis (RA) can strike anywhere, and that includes your feet. In fact, foot inflammation and pain is an early symptom for many people. Foot symptoms in RA can take many forms, including pain in the joints, stiff ligaments, or constant aching. Symptoms are generally worse after a lot of standing, walking, or running.
The onset of foot pain is gradual for some people with RA and immediate for others. At some point, though, most people with this disease discover that their foot joint pain makes it very painful to walk.1
How RA Affects Feet
Rheumatoid arthritis is an autoimmune condition in which your immune system mistakes a fluid in your joints (synovial fluid) and the joint lining (synovium) for a dangerous pathogen and tries to destroy it.
This results in damage and inflammation that makes your joints swell up and feel warm.2 The small joints, such as those in the feet, are the most common targets of these attacks.
Eventually, chronic inflammation thickens the synovium and causes cartilage and bone to erode. In the feet and toes, this can cause deformities in the joints, diminished range of motion, and considerable pain. Walking, standing, and even wearing shoes can become difficult.
Proper treatment may help reduce the damage and inflammation to your foot joints and prevent or delay deformities and other problems.
RA vs. Osteoarthritis
When you first start having foot pain, you may wonder if it's due to osteoarthritis (OA), which is more common than rheumatoid arthritis.
While there's no clear-cut way to tell other than to get a medical diagnosis, OA and RA do have some key differences.
RA Foot Pain
Usually affects both feet at once
Morning stiffness generally lasts longer than half an hour4
OA Foot Pain
Most often affects only one foot
Stiffness tends to be easier to relieve in the morning, often diminishing in less than half an hour or with a few minutes of stretching
RA and Foot Deformities
When it comes to the feet, rheumatoid arthritis typically affects the metatarsophalangeal (MTP) joints of the toes. It can, especially without treatment, lead to significant foot deformities.
Lateral drift: Over time, the toes may "drift" outward, toward the little toe.3 This is sometimes called a lateral drift or lateral deviation and it looks like the toes are leaning.
Bunions: The feet may develop bunions (hallux valgus), which are painful bony lumps.
Contractures: RA may also cause your forefoot to shift, which can lead to permanent shortening of muscles or tendons in your toes (i.e., contractures). A well-known type of contracture is hammertoes, which is when the toe is permanently flexed and curled under. Contractures can lead to calluses and pain under the ball of the foot.
Flat feet (pes planus): The talonavicular joint, which is part of the foot's arch, can become destabilized and cause the arch to collapse.1
All of these changes to a foot's structure and shape can make finding a comfortable shoe more difficult for someone with RA.
RA Foot Deformities: Diagnosis and Treatment
Other Foot Problems in RA
People with RA can have foot symptoms that aren't related to deformities, as well, as the disease can impact just about any joint in the foot.
This is a common recurring problem for people with RA and can occur at the back or underside of the heel.
Inflammation in the feet may lead to conditions associated with heel pain, including:
Plantar fasciitis (heel spur syndrome)
Retrocalcaneal bursitis, which occurs when a fluid-filled sac behind the heel bone (bursa) becomes inflamed and causes pain and swelling
Nerve Entrapment Syndromes
When RA inflames the synovium, the swelling can compress nerves. One common nerve entrapment in the foot is called tarsal tunnel syndrome, which causes burning, tingling, or shooting pain in the area of the foot's arch and sole.
A rheumatoid nodule appears as a lump beneath the skin, usually over a bony prominence or tendon. In the foot, a rheumatoid nodule may appear over the Achilles tendon or on the side of the big toe if a bunion (hallux valgus) is present.
The inflammation of RA can affect small blood vessels, which can cause rashes or sores on the lower legs and feet. Splinter hemorrhages, which are small areas of broken blood vessels on the sides of your toenails or fingernails, are also possible.
Managing Foot Pain in RA
The systemic treatments you get for rheumatoid arthritis may go a long way toward relieving your foot pain. However, you may need to find other ways to help manage foot-specific pain and cope with deformities.
Common strategies include:1
Anti-inflammatory drugs (NSAIDs)
The approach that works best for you will depend on several factors, including what joints are affected and to what degree.
If these conservative approaches aren't successful, you may need to consider surgery. Deformities like bunions and hammertoes can often be surgically treated.
In some cases, doctors fuse together the bones that form a joint to limit motion, which reduces pain. Depending on the specific bones that are fused, you may or may not notice the loss of motion.1
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A Word From Verywell
While not everyone with RA will develop foot problems, the majority of people do have at least some foot-related symptoms. The most important thing to note, though, is that you have a lot of drug options as well as conservative treatments that can make a tremendous difference in managing all aspects of the disease.
A close relationship with your rheumatologist—who will work to relieve your pain and inflammation, halt joint damage, and improve your sense of well-being—will ensure the best outcomes possible throughout the course of your disease.