Rheumatoid arthritis causes long-term inflammation in the joints. This can change the shape of the joints, often in the hands, fingers, and feet.
Doctors can assess and visualize the effects of RA using imaging methods, such as X-rays, ultrasound, and MRI scans. In this article, we discuss what RA looks like and which parts of the body it can affect.
RA affects around 1.3 million people in the United States and around 1 percent of people worldwide.
The primary symptom of RA is inflammation in the joints, which causes pain, swelling, and stiffness. RA typically affects the same joint on both sides of the body.
The physical effects of RA in the joints can include:
- changes in the shape of joints
- nodules, which are small, firm lumps near the joint
- inflamed bursa, where fluid accumulates in the bursa near joints and may become visible
- circulation problems, which can cause fingers or toes to turn blue
- skin and nail problems, though this is more common with psoriatic arthritis
RA in the joints can also lead to vasculitis, which can cause small lesions to appear around the fingers, nails, or lower legs. However, this is becoming less common due to effective treatments and improved ways of detecting RA at an early stage.
Symptoms of RA tend to come and go in phases called flares. These flares can develop over many weeks, but they can also appear rapidly within a few days.
Along with changes in the joints, RA also causes other symptoms, including:
- high temperature
- appetite changes
- weight loss
- restricted mobility
RA commonly affects the hands and wrists. It can cause swelling around the knuckles, finger joints, and wrists. This swelling can cause significant discomfort and stiffness and restrict a person's ability to use their hands fully.
The swelling and stiffness in the hands typically peak in the morning, then gradually decline throughout the day.
Extended periods of inflammation can cause the finger and wrist joints to change shape. This has a significant impact on the mobility of the hands, which can make it more difficult for people to perform daily tasks.
RA can also affect the joints of the foot and ankle. Up to 90 percent of people with RA will experience symptoms in their feet.
In fact, people often develop symptoms in their little toe before signs appear in their hands.
People may notice the symptoms in their feet because they can affect mobility. This is because walking exerts a constant pressure in and around the feet.
The foot joints most commonly affected include:
- the small joints in the toes called the interphalangeal joints
- the large joint on the big toe called the metatarsophalangeal (MTP) joint
- the joint connecting the foot with the ankle called the subtalar joint
- the ankle joint, although this is less common
RA can damage tendons, ligaments, and other tissues surrounding the joints. For example, it can affect the Achilles tendon, which connects the calf to the heel bone. Nodules can also appear in this area.
Damage to the tendons can cause the toes to become twisted, leading them to cross over each other. The toes may curl downwards and appear claw-like. This condition is commonly known as hammer toe.
Damage to the tendons and ligaments in the middle of the foot can cause the arch of the foot to collapse.
Problems with the MTP joint can create bony protrusions on the sole, which is painful and may affect how someone walks.
Changes to the shape of the toes and feet can cause the joints to rub on shoes or the toes to rub against each other. This can cause other problems, such as:
Many people will only experience mobility problems when they have an RA flare-up. Flare-ups may last for several months if not treated effectively.
Many people also experience RA in the knee joint.
The knee joint contains cartilage to prevent the bones from scraping against each other. Inflammation can damage this cartilage, causing the bones to rub together. This tends to occur in people who experience chronic RA or do not receive effective treatment to control the inflammation.
Some people may also develop abnormal bone growths in the knees, called osteophytes.
RA in the knee can cause pain and stiffness and may affect a person's walking and mobility.
RA can present in different ways, with each type producing slightly different symptoms.
RA can present as:
Polyarthritis is not a separate type of arthritis, but rather a pattern of arthritis. Polyarthritis is when five or more joints are affected by arthritis.
Polyarthritis typically involves chronic inflammation and can have a severe impact on mobility.
There are several different types of polyarthritis, which can impact the body in different ways. For example, lupus is a type of polyarthritis that can also affect the skin, kidneys and the central nervous system (CNS).
Juvenile arthritis, also known as pediatric rheumatic disease, describes a group of autoimmune and inflammatory conditions that affect people under the age of 16.
One of the most common forms of arthritis, juvenile idiopathic arthritis, falls under this category.
There are several different types of juvenile idiopathic arthritis, and symptoms vary between them. However, inflammation in the joints is common to them all.
RA affects people in different ways. The differences will often depend on which joints are inflamed. For example, inflammation in the ankle and feet joints can restrict a person's ability to walk.
These issues are usually only temporary because symptoms tend to flare up and go away again. Sometimes, however, these flare-ups can last for months.
However, doctors can usually recommend treatments that can prevent prolonged flares and subsequent damage.