Osteoarthritis is a disease that affects the joints only; generally the joints of the hips, knees, and hands are the most likely to be affected. This disease is more common in people over fifty, and is more common in women.
The most common cause of osteoarthritis is chronic joint stress such as that caused by running. Joint injury or diseases can also lead to the development of osteoarthritis. Whatever the cause, the precipitating factor is always some type of joint damage.
Essentially, osteoarthritis is caused by a dysfunction in the way joint cartilage is repaired after sustaining damage. Cartilage is a spongy, smooth substance that covers joint surfaces and allows joints to move with less friction. Chronic damage can cause cartilage to wear away or be repaired ineffectively, leading to uneven deposits of cartilage on the joint surfaces. Over time, these joint problems begin to cause pain and inflammation. In addition, bony deposits grow around the joints, which can worsen these symptoms. These bony growths also cause the joints to become stiffer and less flexible.
Rheumatoid arthritis is an autoimmune disease that primarily affects the joints, and can also affect the eyes, skin, lungs, and heart. The main symptoms of this disease are joint swelling, pain, inflammation, and stiffness, which can progress to reduced mobility depending on the affected joints. Generally the joints of the feet and hands are affected; however sometimes other joints might become inflamed too. It is common for multiple joints to be affected at the same time.
Rheumatoid arthritis is an autoimmune disease, which means it is caused by abnormal immune system behavior. A healthy immune system is capable of distinguishing accurately between “self" and “not-self" tissues and cells. “Self" tissues are those of the body, while “not-self" refers to everything else, including bacteria, viruses, and parasites. When the immune system is functioning correctly, it is sensitized to attack only not-self cells and tissues. In an autoimmune disease, the immune system becomes dysfunctional and is sensitized to attack one or more types of self proteins.
In people with rheumatoid arthritis, the immune system has become sensitized to proteins that are located in joints. The immune system mounts an inflammatory response against these proteins, causing joint inflammation which leads to the other symptoms of the disease.
This disease can occur in anyone of any age, but is most common in women aged between thirty and fifty.
Osteoarthritis Vs. Rheumatoid Arthritis: Comparison Summary
Causes: Osteoarthritis is caused by “mechanical" joint damage such as chronic stress caused by weight-bearing exercise, or a traumatic injury.
Rheumatoid arthritis is an autoimmune disease, which means it develops as a result of immune system dysfunction.
Symptoms: Both diseases cause severe joint pain and inflammation which becomes worse over time. Rheumatoid arthritis can sometimes cause symptoms in other parts of the body in addition to the joints.
Treatment: Early diagnosis and treatment is helpful for both osteoarthritis and rheumatoid arthritis. For both diseases, the main focus is on reducing inflammation and managing pain with medication.
Physical therapy and lifestyle changes can also be useful to improve muscle strength to help reduce joint strain. In the case of rheumatoid arthritis, dietary changes can help reduce the severity of symptoms.
Prognosis: Osteoarthritis is a progressive disease; once joint damage has been sustained it cannot be reversed. For some people the disease is manageable with medication. In some cases, however, the disease can progress far enough that joint replacement surgery is required.
Rheumatoid arthritis is a chronic, incurable disease that can go into remission. A remission is a period of months or even years in which symptoms disappear entirely. Remission can end at any time.
Prevention: Osteoarthritis is often thought of as a disease that is inevitable for seniors, but this is not the case. Good joint care is an important preventative measure. Avoiding heavy weight-bearing exercise such as running, maintaining good posture, and avoiding putting excessive stress on the joints are all important measures. Maintaining a healthy weight, and building up muscle strength with exercise are also useful.
In contrast, rheumatoid arthritis cannot be prevented with these types of joint care measures. This is because the disease process that causes this type of arthritis is unpredictable: it is more of an immune system “accident" than something which can be caused by an injury or by overstressing the joints.
Arthritis Foundation US: Rheumatoid Arthrtitis
National Health Service UK: Osteoarthritis
National Institute of Health MedlinePlus: Osteoarthritis Pages
National Institute of Health MedlinePlus: Rheumatoid Arthritis Pages
The Mayo Clinic: Osteoarthritis
The Mayo Clinic: Rheumatoid Arthritis