How Rheumatoid Arthritis Affects Different Body Systems

Rheumatoid arthritis (RA) is a progressive disease that mainly affects the joints. According to the American College of Rheumatology, RA is the most common type of autoimmune arthritis, affecting more than 1.3 million Americans.

RA can affect many different body systems, including the musculoskeletal system, integumentary system, ocular system, immune system, circulatory system, and more. Read to find out more about these effects.

Musculoskeletal System 

Your musculoskeletal system provides the body with movement, stability, shape, and support. This body system is divided into two systems—the muscular system and the skeletal system.

Skeletal system: The main part of the skeletal system is bone. The bones come together at the joints, providing the body with a stable and mobile skeleton. The bones and joints are supported by other necessary structures—the articular cartilage, ligaments, and bursae.

Articular cartilage is the smooth, white tissue covering the ends of bones where they meet with the joints. The ligaments are the short, tough, and flexible fibers of connective tissues that connect bones and cartilage and hold together joints. The bursae are fluid-filled sacs that provide cushion to the moving parts of joints.

Muscular system: The muscular system includes all the muscles of the body. The skeletal muscles, for example, are the ones that support the joints to produce movements. The muscular system also contains tendons that attach muscles to bones. 

RA in the Skeletal System 

One of the first indications of RA is inflammation in the small joints of the hands and feet. Often, RA is symmetrical—affecting both sides of the body at once. Symmetry is key to diagnosing RA. Sometimes, RA does not cause symptoms on both sides, especially early on in the disease. The condition will become symmetrical as RA progresses.

Additional joints symptoms of RA include pain, swelling, stiffness, and tenderness. These are usually much worse in the morning and can last for 30 or more minutes. RA can also cause tingling or burning in the joints.

RA symptoms can affect any of your joints, especially as RA progresses. This includes symptoms in the hands, feet, shoulders, elbows, hips, knees, and ankles.

As the disease progresses, it will affect tendons, ligaments, and muscles. These symptoms will eventually lead to range-of-motion problems and difficulty with moving your joints. Long-term inflammation in affected joints will cause those joints to become damaged and deformed.

Having RA can put you at a higher risk for osteoporosis—a condition that bone loss and weakness. This weakness can eventually lead to bone fractures (breaks).

Ongoing inflammation in your wrists may lead to a condition called carpal tunnel syndrome, which can make it harder to use your wrists and hands. This same inflammation can cause weakness and damage the bones of your neck and cervical spine causing severe, ongoing pain.

RA in the Muscular System

When inflammation makes it harder to move your joints, the attached joints will get weak. According to a 2017 report in the journal EBioMedicine, a 25–75% reduction in muscle strength has been observed in people with RA when compared to others without RA of the same ages.

People with RA can develop a condition called rheumatoid myositis that causes weakness, swelling, and pain. While rheumatoid myositis is poorly understood, researchers speculate a number of causes, including inflammation, the medications used to treat RA, impaired joint flexibility, and reduced activity levels.

Rheumatoid Arthritis Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Download PDF

Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life.

Sign Up

You're in!

Thank you, {{form.email}}, for signing up.

There was an error. Please try again.

Integumentary System

The integumentary system includes the skin, hair, and nails, and RA can affect all three. 

Skin

The most common skin problems associated with RA are rheumatoid nodules, skin rashes and ulcers, and skin reactions from the medications used to treat RA. 

Rheumatoid nodules: These hard lumps of tissue tend to affect people who are rheumatoid factor (RF) positive. RFs are proteins produced by the immune system and are responsible for it mistakenly attacking healthy joints, glands, and other body cells.

Rheumatoid nodules will vary in size­—some as small as a pea and others as large as a ping pong ball. They develop under the skin in bony areas like the fingers, ankles, and elbows. Sometimes, nodules can form on the lungs.

RA treatments, including disease-modifying anti-rheumatic drugs (DMARDs) and corticosteroids, may help to shrink nodules, but some people might need surgery if nodules get too big, become infected, or are painful. 

Nodules commonly occur in areas of pressure. For example, many people often put pressure on the back of the elbow (olecranon) by resting it on a table or chair. This is a very common area of involvement. If the nodule is removed, it can commonly recur after a number of years.

Skin rash and ulcers: For some people, nodules are a sign of rheumatoid vasculitis (RV), a condition where the small and medium-sized blood vessels are inflamed. When RV affects the large blood vessels, a painful rash can occur, usually on the legs.

Rashes from RV may appear as red and painful patches or red, itchy dots. The fingertips are the most commonly affected skin area in RA but any skin area can be affected. If RV is severe, skin ulcers (open sores or wounds) can form and become infected. 

Medication side effects: The medications you take to treat RA can cause skin problems, including rashes, easy bruising, and skin sensitivity. Medication-related skin rash is usually a sign of an allergic reaction, so it is a good idea to let your healthcare provider know if your skin breaks out and feels itchy.

Some RA medications cause the skin to thin out or interfere with blood clotting, which will cause you to bruise much easily. Some RA drugs—like methotrexate­—can make your skin more sensitive to the sun. That means you should avoid direct sunlight, wear protective clothing when outdoors, use sunscreen, and avoid tanning beds while on these medications. 

Hair 

Some people with RA experience hair loss as a disease symptom, and others as a side effect of RA treatment. Fortunately, hair loss tends to be a rare complication and when it does happen, it isn’t severe. This means RA will thin your hair, but you will not lose it in patches. 

One of the most common medications used to treat RA—methotrexate—is responsible for hair loss. This is because it causes cells to stop growing, which includes the cells that cause inflammation and those that promote hair follicle growth.

A study reported in 2019 in the Polish journal Polski Merkuriusz Lekarski finds that 24.9% percent of study participants on methotrexate were experiencing hair loss, and the majority—60%—were women.

Nails 

While there isn’t a lot of research related to RA’s effects on fingernails and the nails of your toes, there are studies that have mentioned these effects to some degree.

For example, a 2017 report in the Indian Journal of Dermatology notes various nail abnormalities in RA. These can include nail thickening, pitting (deep holes in the nails), discoloration, nail bleeding in areas of skin near nails, ingrown nails, and surface and curvature abnormalities.

One German study mentioned in this report found that around 27% of people had nail changes related to RA.

Ocular System

Your ocular system consists of your eyes and its central visual system. And RA can cause all sorts of eye problems, including dry and inflammation-related conditions like keratoconjunctivitis sicca, scleritis, and uveitis.

• Keratoconjunctivitis sicca causes eye dryness and reduced tear production, which leads to redness and irritation.
• Scleritis affects the sclera—the white part of the eye—causing inflammation and pain.
• Uveitis inflames the uvea—the inner part of the eye—leading to redness, pain, and blurred vision.

Symptoms that indicate RA has affected your eyes include:

• Dryness
• Redness
• Pain
• Blurred vision
• Sensitivity to light
• Dry and gritty eyes

Immune System

Your immune system is made up of a complex network of organs, cells, and tissues that work together to fight off infections and other diseases. RA is caused when the immune system attacks healthy joints because it thinks they are foreign invaders.

RA also increases your risk of all types of infections. Observational studies show the risk of infection in people with RA is twice that of others in the general population. Because the immune system is busy attacking joints and healthy tissues, it is too busy to protect you against infection.

The medications you take for RA will also increase your risk of infection because they suppress immune system responses. Corticosteroids pose the highest risk, according to a study reported in 2016 in the journal PLoS Medicine.

Circulatory System 

The circulatory system—also called the cardiovascular system or the vascular system—is the organ system that allows for blood circulation and transport of oxygen, hormones, nutrients, carbon dioxide, and blood cells in the body to provide nourishment, help with fighting disease, and stabilizing body temperatures and pH levels.

There are two major diseases of the circulatory system that RA can increase your risk for—heart disease and vasculitis.

Heart Disease

People with RA have a higher risk for cardiovascular events—coronary artery disease, heart attack, arrhythmia, heart failure, peripheral artery disease, etc., especially compared to others in the general population. They also have a higher risk of cardiovascular, respiratory, and all-cause mortality.

RA can also cause pericarditis, a condition where the sac around the heart is inflamed, and myocarditis—inflammation of the heart muscle.

Vasculitis

Vasculitis is a serious complication of RA, resulting from ongoing inflammation of the blood vessels. This chronic inflammatory process eventually causes blood vessels to become weak and expand or narrow to the point of reducing or stopping blood flow.

The most commonly affected blood vessels are the arteries responsible for transferring blood to the nerves, skin, heart, and brain. Vasculitis can also affect the veins.

Anemia

RA can also increase your risk for anemia­­—a condition where the body lacks enough healthy red blood cells to carry sufficient amounts of oxygen to the body’s tissues. The two types of anemia associated with RA are anemia of chronic inflammation and iron deficiency anemia.

Chronic inflammation from RA can lower the production of red blood cells in the bone marrow and release proteins that affect how your body uses iron. Inflammation can also affect the production of erythropoietin, the hormone that regulates the production of red blood cells.

Nervous System

RA can affect the central nervous system (CNS), the spine, and the brain. According to a 2015 review of studies in the journal Autoimmunity Reviews, neurological manifestations are quite common in RA. This includes depression, cognitive dysfunction, behavior changes, spinal cord compression, and peripheral nerve involvement. 

Potential causes of neurological problems include inflammation, nerve compression problems in bones and joints, side effects of medications, and coping problems associated with RA. 

Digestive System

People with RA experience gastrointestinal (GI) problems. In fact, research shows they struggle more with GI issues than others without the disease.

A study reported in 2012 in the Journal of Rheumatology followed 813 people with RA and 813 people without RA for 10 years. Researchers found the people with RA had a 70% higher risk for upper GI problems and a 50% greater chance for lower GI problems, in comparison to people without RA. 

Upper GI events include perforations (holes in the wall of the GI tract), bleeding, ulcers, obstruction, and inflammation of the esophagus, a condition called esophagitis. Lower GI problems include colitis (swelling of the large intestine), and diverticulitis (inflammation of the small sacs that line the intestines). GI bleeding from ulcers is often due to medications such as NSAIDS. This risk is increased in those patients who take a combination of NSAIDS and corticosteroids.

Symptoms of GI problems may include dysphagia (difficulty swallowing), stomach pain, indigestion (upper abdominal discomfort), heartburn, black, tarry, or bloody stools, constipation, diarrhea, or leaking of stool.

Respiratory System

The respiratory system is the network of organs and tissues that help you to breathe. This system includes the airways, lungs, blood vessels, and the muscles that power the lungs. All of these parts work together to move oxygen through your body and to get rid of waste gases like carbon dioxide. 

Studies have confirmed a strong connection between RA and lung problems. Lung problems associated with RA include pleurisy, rheumatoid lung nodules, interstitial lung disease, and pulmonary hypertension. 

Pleurisy: This condition affects the pleura, the two large, thin layers of tissue that separate the lungs from the chest wall. In people with RA, the pleura becomes inflamed, leading to breathing problems and pain.

Rheumatoid lung nodules: Nodules that form on the lungs are usually harmless. However, in some cases, they can cause infection, a collapsed lung, or a pleural effusion where there is fluid buildup in the linings of the lungs and chest cavity.

Interstitial lung disease (ILD): ILD is part of a large group of disorders that cause progressive lung tissue scarring. This scarring is associated with long-term inflammation and can cause shortness of breath and a chronic dry cough.

Pulmonary hypertension: This is a type of high blood pressure that damages the arteries in the lungs and heart. 

Mucous Membranes

The mucous membranes line many tracts and structures of the body and affect multiple body systems. Mucous membranes include the mouth, nose, eyelids, the windpipe, lungs, stomach, intestines, the vagina, and the ureters, urethra, and urinary bladder. 

A condition called Sjogren’s syndrome can affect some of the mucous membranes. Sjogren’s affects between 400,000 and 3.1 million adults in the United States, according to the American College of Rheumatology.

When it is secondary to a primary cause like RA, it is called secondary Sjogren’s syndrome. A study reported in 2020 finds the prevalence of secondary Sjogren’s in people with RA is about 30%.

In people with RA, Sjogren’s often affects the tear and saliva glands, leading to dry eyes, dry skin, and dry mouth. It can cause the eyes to be dry and red, and cause blurry vision. When Sjogren’s affects the mouth and throat, it can make it hard to eat or swallow. And chronic dry mouth can lead to tooth decay, oral infections, and gingivitis. 

Sjogren’s can cause swollen glands in the neck and face and dry nasal passages. Women with the condition may experience vaginal dryness. 

A Word From Verywell 

Early diagnosis and treatment can slow down RA progression, reduce or prevent its effects on multiple body systems, and improve your quality of life.

Make sure you keep your healthcare provider apprised of any new symptoms you experience with RA, so they can adjust your treatment as needed. They may request testing to determine the source of new symptoms or refer you to other specialists to help manage symptoms and conditions affecting body systems other than the musculoskeletal system.