Email a Friend
Print ArticleRheumatoid Arthritis Health Center
The Causes of Rheumatoid Arthritis
Osteoarthritis is the result of the wear and tear on joints. Rheumatoid arthritis, on the other hand, occurs when the immune system goes haywire and begins attacking joint linings. This chronic inflammatory condition also affects other tissue, but the joints are usually the most severely affected.
Here is what we know about the causes of rheumatoid arthritis.
What causes rheumatoid arthritis?
Although doctors aren't sure of the exact cause, it's thought that rheumatoid arthritis may result from a combination of genetics and environmental triggers. Some researchers believe an infection with a bacteria or virus can trigger the development of rheumatoid arthritis in someone who's genetically susceptible. However, to date, no infection or organism has been found that could be said to be the cause.
As rheumatoid arthritis develops, some of the body's immune cells recognize a protein as a foreign intruder. The exact protein is unknown and may be one of any number of potential candidates. Some of them are produced by infection, such as a viral, bacterial, or fungal infection. Other candidate proteins may have a genetic connection or stem from other causes.
Whatever the source, cells called lymphocytes react to this protein. The reaction then causes the release of cytokines, which are chemical messengers that trigger more inflammation and destruction. With rheumatoid arthritis, the main target of inflammation is the synovium, the thin membrane that lines the joints. The inflammation also spills to other areas in the body causing joint damage, inflammation, chronic pain, fatigue, and loss of function.
There are many cytokines, but the most important in rheumatoid arthritis are tumor necrosis factor (TNF) and interleukin-1. These cytokines are thought to trigger the process of joint damage in rheumatoid arthritis. Some treatments for rheumatoid arthritis aim to block these cytokines, reducing inflammation and joint damage.
What risk factors increase the chance of rheumatoid arthritis?
Rheumatoid arthritis is more common in women than in men. In fact, 70% of the patients with rheumatoid arthritis are women. In addition, there's an increased risk of rheumatoid arthritis in women who have never been pregnant and in those who have recently given birth.
Rheumatoid arthritis has a genetic link, and the disease can run in families. People with specific human leukocyte antigen (HLA) genes have a greater chance of developing rheumatoid arthritis than people who do not have the HLA genes. Still, not everyone with the HLA genes develops rheumatoid arthritis. In other words, genes can increase the risk of rheumatoid arthritis, but other unknown factors are also involved.
Older age and cigarette smoking may increase the risk of getting rheumatoid arthritis. So can stress. In fact, many patients with rheumatoid arthritis tell of having an extremely stressful life event within the six months before the disease appeared.
Symptoms of rheumatoid arthritis include joint pain, swelling, stiffness, and fatigue -- which can be mild or severe. Doctors recommend treating rheumatoid arthritis early, before there are visible signs of joint destruction.
WebMD Medical Reference
Rheumatoid Arthritis Guide 
- Learn about Treatment for Moderate to Severe Rheumatoid Arthritis (RA)
- Is This RA Treatment Right For You?
- Some Fast Facts
Important Safety Information you should know about HUMIRA® (adalimumab).
Serious infections have happened in patients receiving HUMIRA. These infections include TB (tuberculosis) and infections caused by viruses, fungi, or bacteria that have spread throughout the body. Some patients have died from these infections.
Before starting HUMIRA:
Tell your doctor if you think you have an infection, are being treated for an infection, have signs of an infection (such as a fever, cough, or flu-like symptoms), have any open sores on your body, have warm, red, or painful skin, get a lot of infections or have infections that keep coming back, have or had hepatitis B infection, take the medicine Kineret (anakinra), have TB or have been in close contact with someone who has TB, have lived in an area where TB or histoplasmosis is common, or were born in, lived in or traveled where there is more risk for getting TB. Your doctor should test you for TB before starting HUMIRA. If your doctor prescribes any medicine for the treatment of TB, you should start taking it before starting HUMIRA and take the full course of TB medicine prescribed.
Tell your doctor if you have any numbness or tingling, or have a disease that affects your nervous system such as multiple sclerosis or Guillain-Barré syndrome, have heart failure or other heart conditions, are scheduled for major surgery, are pregnant, become pregnant, plan to become pregnant or are breastfeeding. Tell your doctor if you are allergic to HUMIRA or any of its ingredients or are allergic to rubber or latex. The needle cover of the prefilled syringe and the pen contain dry natural rubber.
Also, tell your doctor if you have recently received or are scheduled for any vaccines. Except for live vaccines, patients may still receive vaccines while on HUMIRA. It is recommended that children with juvenile idiopathic arthritis be brought up to date with all immunizations prior to starting HUMIRA.
After starting HUMIRA:
Call your doctor right away if you get an infection, or any sign of an infection including a fever, feeling very tired, cough, flu-like symptoms, warm, red or painful skin or if you have any open sores on your body. HUMIRA can make you more likely to get infections or make any infection that you may have worse.
Possible side effects of HUMIRA:
Serious side effects, which sometimes lead to death, have happened in patients taking HUMIRA.
- Serious infections. These infections include TB (tuberculosis) and infections caused by viruses, fungi, or bacteria. Your doctor will examine you for TB and perform a test to see if you have TB. If your doctor feels that you are at risk for TB, you may be treated with medicine for TB before you begin treatment with HUMIRA and during treatment with HUMIRA. Even if your TB test is negative your doctor should carefully monitor you for TB infections while you are taking HUMIRA. Patients who had a negative TB skin test before receiving HUMIRA have developed active TB. Tell your doctor if you have any of the following symptoms while taking or after taking HUMIRA: cough, low-grade fever, weight loss, or loss of body fat and muscle.
- Certain types of cancer. There have been cases of certain kinds of cancer in patients taking HUMIRA or other TNF blockers. Patients with RA, especially more serious RA, may have a higher chance for getting a kind of cancer called lymphoma. Some patients receiving HUMIRA have developed types of cancer called non-melanoma skin cancer (basal cell cancer and squamous cell cancer of the skin), which are generally not life threatening if treated. Tell your doctor if you have a bump or open sore that doesn't heal.
- Allergic reactions. Signs of a serious allergic reaction include skin rash, a swollen face, or trouble breathing.
- Hepatitis B virus reactivation in patients that carry the virus in their blood. Tell your doctor if you have any of the following symptoms: feel unwell, poor appetite, fatigue, fever, rash or joint pain.
- Nervous system problems. Signs and symptoms include: numbness or tingling, problems with your vision, weakness in your arms or legs, and dizziness.
- Blood problems. Symptoms include a fever that does not go away, bruising or bleeding very easily, or looking very pale.
- New heart failure or worsening heart failure you already have. Symptoms include shortness of breath or swelling of your ankles or feet, or sudden weight gain.
- Immune reactions including a lupus-like syndrome. Symptoms include chest discomfort or pain that does not go away, shortness of breath, joint pain, or rash on your cheeks or arms that gets worse in the sun.
Call your doctor or get medical care right away if you develop any of the above symptoms. Your treatment with HUMIRA may be stopped.
Common side effects of HUMIRA are: injection site reactions (redness, rash, swelling, itching or bruising), upper respiratory infections (sinus infections), headaches, rash and nausea.
These are not all the side effects with HUMIRA. Ask your doctor or pharmacist for more information.
Information You Should Know About HUMIRA® (adalimumab).
HUMIRA is used to reduce the signs and symptoms of moderate to severe rheumatoid arthritis in adults, may prevent further damage to your bones and joints, and may help your ability to perform daily activities. HUMIRA can be used alone or with methotrexate or with certain other medicines. HUMIRA is used to reduce the signs and symptoms of moderate to severe polyarticular juvenile idiopathic arthritis in children 4 years of age and older. HUMIRA can be used alone or with methotrexate or with certain other medicines. HUMIRA is used to reduce the signs and symptoms of psoriatic arthritis in adults, may prevent further damage to your bones and joints, and may help your ability to perform daily activities. HUMIRA can be used alone or with certain other medicines. HUMIRA is used to reduce the signs and symptoms of ankylosing spondylitis in adults. HUMIRA is used to reduce the signs and symptoms of moderate to severe Crohn's disease in adults who have not responded well to conventional treatments. HUMIRA is also for these adults with moderate to severe Crohn's disease who have lost response or are unable to tolerate infliximab. HUMIRA is used to treat moderate to severe chronic (lasting a long time) plaque psoriasis in adults who are under the ongoing care of a physician, have the condition in many areas of their body and who may benefit from taking injections or pills (systemic therapy) or phototherapy (treatment using ultraviolet light alone or with pills).
HUMIRA is taken by injection.
64S-154126
Find a hospital by procedure or condition
WebMD Health Check
What's Your Exercise Personality?
Finding an activity that suits your personality could be the key to a long and healthy life.
Most Popular Stories
WebMD Special Sections
