Arthritis symptoms in feet
There are 33 joints in a single foot. Each of your feet also contains 26 bones, plus a host of muscles, tendons, and ligaments, making them a prime target for rheumatoid arthritis.
Rheumatoid arthritis (RA) is a chronic inflammatory disorder in which your immune system mistakenly attacks the membrane lining surrounding your joints. It usually targets the smaller joints first, such as those in the hands and often the feet.
More than 90 percent of people with rheumatoid arthritis will develop pain, stiffness, swelling, or other symptoms in the foot and ankle throughout the disease, according to the American Academy of Orthopedic Surgeons. You can read here about common symptoms of rheumatoid arthritis.
How rheumatoid arthritis affects the feet
Joints are covered with a lining called the synovium. Their job is to lubricate the joint, so it moves more easily. Unfortunately, rheumatoid arthritis causes hyperactivity in this lining. As a result, the synovial membrane becomes inflamed, thickened, and produces excess joint fluid. That extra fluid, along with inflammatory chemicals released by the immune system, causes swelling, damages cartilage, and softens the bone within the joint. “As a systemic disease, rheumatoid arthritis also affects the ligaments and surrounding soft tissue,” says Dr. Brett Sachs, DPM, a foot and ankle surgeon in Colorado. “When that happens, the joints start to weaken, and that's when deformities can occur,” explains Dr. Sachs, an American College of Foot and Ankle Surgeons member.
"Rheumatoid arthritis tends to affect the joints in the feet more quickly in part because they are smaller," says Dr. Sachs. Research shows that in about 20 percent of rheumatoid arthritis patients, foot and ankle symptoms are the first signs of the disease.
Rheumatoid arthritis can cause pain, swelling, stiffness, and tenderness in the joints of the foot. If the disease progresses, the joints can become deformed and disabled. It is common to have pain and tenderness in the metatarsal region of the foot. The joints between the foot and toes (metatarsophalangeal joints) swell and become displaced, causing the toes to bend and overlap. The big toe can bend inward (bunion). The middle fingers can be deformed by bending like a claw (hammer toe).
What does rheumatoid arthritis feel like in the feet?
When your feet are affected by rheumatoid arthritis, you may experience swelling, redness, and a feeling of warmth around the affected joints. Pain is also very common. In a study comparing foot problems in rheumatoid arthritis patients against people without arthritis, 98 percent of rheumatoid arthritis patients had foot pain, and 96 percent reported some difficulty in function, compared with 76 percent and 66 percent, respectively, in the healthy group.
Compared to osteoarthritis, which usually affects a specific joint, rheumatoid arthritis usually occurs in the same joints on both sides of your body, so it commonly affects both feet simultaneously. Symptoms may appear and then go into periods of remission. Here's more information on coping with rheumatoid arthritis pain.
Over time, rheumatoid arthritis can cause joints to become misshapen and out of place. Specific foot problems caused by rheumatoid arthritis include:
Six symptoms that indicate arthritis in the feet
If you have been feeling intense pain in your feet for some time, there is a great possibility that arthritis is the cause of your discomfort.
Remember that arthritis causes swelling and pain in the cartilage and lining of the joints. If these symptoms affect your feet, it's time to see a podiatrist, notes the American Podiatric Medical Association.
Pain in the toe
“The medical term is metatarsalgia, and it's the most common foot problem associated with rheumatoid arthritis,” says Dr. Jonathon Rouse, DPM, a Nebraska-based podiatrist and spokesperson for the American Association of Podiatric Medicine. “Once the intrinsic (or deeper) muscles in your foot lose their stabilizing forces, dislocations or deformities of the metatarsophalangeal joint (which connects the toe to the foot) can occur, increasing pressure on the forefoot, and it causes pain and inflammation in the ball of the foot,” explains Dr. Rouse.
People with rheumatoid arthritis may also experience fat pad atrophy or thinning and wearing away of the normal fat pad that runs across the ball of the foot, which can increase pain.
“This hard, painful, bony lump that forms at the joint at the base of the big toe is a common complaint among rheumatoid arthritis patients,” says Dr. Sachs. It occurs when some of the bones in the front of the foot move out of place, causing the big toe to push against the next and the joint at the base of the big toe to stick out. Sometimes the big toe turns so much that it moves over the toe next to it.
Hammer toe and nails
Weakened ligaments from rheumatoid arthritis can cause joint deformities, conditions in which the toes are permanently bent and curved, like a claw. For example, the Hammer toe on the second toe is common in people who have a bunion on the big toe.
“As rheumatoid arthritis progresses, the back of the foot (or heel region) will begin to lose stability,” says Dr. Rouse. The plantar fascia, a ligament that connects the heel to the forefoot, will still try to do its job and support the foot arch; however, additional stress and inflammation will weaken the structure and lead to pain.
Changes in the shape of your foot
Flatfoot deformity, a progressive flattening of the foot's arch, can occur in rheumatoid arthritis when tendons, ligaments, and bones shift out of their normal positions, causing pain and discomfort on or off the ankle.
"If rheumatoid arthritis damages the ligaments that support the top of your foot, your arch can also collapse, which can cause the ball of your foot to point outward," according to the American Academy of Orthopedic Surgeons.
Shape changes in the forefoot and toes can create pressure sites that then develop calluses or areas of hard, thickened skin.
All of these changes in foot shape can make it difficult to wear shoes comfortably.
Some people with rheumatoid arthritis develop hard lumps under the skin called nodules, often around pressure points. In the feet, nodules can appear over the Achilles tendon, heel pad, or anywhere on the bone and can cause pain if they rub against shoes or along the floor as you walk.
The group mentions that joint foot arthritis symptoms can include:
Recurring pain or tenderness.
Redness or heat.
Limited movement of a joint.
Stiffness first thing in the morning.
Skin changes, including a rash or growth.
Remember that if you suffer from recurring foot pain and have been suffering for several weeks, it is best to seek medical attention. However, you may find it difficult to decide whether you should see a podiatrist or an orthopedist since, when it comes to arthritis, the problem may not be limited to those extremities. To make the best decision, consider the following:
If your pain is limited to the foot and ankle only, it is advisable to seek the assistance of a podiatrist.
If your pain seems to be more global and may be related to another health problem, seek medical help from an orthopedist.