Inflammation: What You Need to Know

Figure 1. When inflammation occurs normally, chemicals from the body’s white blood cells are released to protect us from foreign substances. Sometimes, however, the white blood cells and their inflammatory chemicals cause damage to the body’s tissues.

What is inflammation?
Inflammation is a process by which the body’s white blood cells and chemicals protect us from infection and foreign substances, such as bacteria and viruses.

In some diseases, however, the body’s defense system (immune system) inappropriately triggers an inflammatory response when there are no foreign substances to fight off. In these diseases, called autoimmune diseases, the body’s normally protective immune system causes damage to its own tissues. The body responds as if normal tissues are infected or somehow abnormal.

What diseases are associated with inflammation?
Some, but not all, types of arthritis are the result of misdirected inflammation. Arthritis is a general term that describes inflammation in joints. Some types of arthritis associated with inflammation include:

Other painful conditions of the joints and musculoskeletal system that are not associated with inflammation include osteoarthritis, fibromyalgia, muscular low back pain and muscular neck pain.

What are the symptoms of inflammation?
Inflammation is characterized by:

Often, only a few of these symptoms are present.

Inflammation may also be associated with general "flu-like" symptoms including:

Figure 2. Inflamed Joint

What causes the symptoms of inflammation?
When inflammation occurs, chemicals from the body’s white blood cells are released into the blood or affected tissues in an attempt to rid the body of foreign substances. This release of chemicals increases the blood flow to the area and may result in redness and warmth. Some of the chemicals cause leakage of fluid into the tissues, resulting in swelling. The inflammatory process may stimulate nerves and cause pain.

What are the results of joint inflammation?
The increased number of cells and inflammatory substances within the joint cause irritation, wearing down of cartilage (cushions at the end of bones) and swelling of the joint lining.

How are inflammatory diseases diagnosed?
Inflammatory diseases are diagnosed after careful evaluation of:

Can inflammation affect internal organs?
Yes. Inflammation can affect organs as part of an autoimmune disorder. The type of symptoms depends on which organs are affected. For example:

Pain may not be a primary symptom of the inflammatory disease, since many organs do not have many pain-sensitive nerves. Treatment of organ inflammation is directed at the cause of inflammation whenever possible.

How are inflammatory joint diseases treated?
There are a number of treatment options for inflammatory diseases including medications, rest and exercise, and surgery to correct joint damage. The type of treatment prescribed will depend on several factors including the type of disease, the person’s age, type of medications he or she is taking, overall health, medical history and severity of symptoms.

The goals of treatment are to:

What medications are used to treat inflammatory diseases?
There are many medications available to decrease joint pain, swelling and inflammation and hopefully prevent or minimize the progression of the inflammatory disease. The medications include:

*Some of these medications are traditionally used to treat other conditions such as cancer, inflammatory bowel disease or organ transplants. However, when "chemotherapy" types of medications (such as methotrexate or cyclophosphamide) are used to treat inflammatory diseases, the doses are significantly lower and the risks of side effects tend to be considerably less than when prescribed in higher doses for cancer.

When you are prescribed any medication, it is important to meet with your physician regularly so he or she can detect the development of any side effects and monitor the efficacy of the medication.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional health information, please contact the Center for Consumer Health Information at the Cleveland Clinic (216) 444-3771 or toll-free (800) 223-2273 extension 43771. If you prefer, you may visit or This document was last reviewed on: 9/3/2006