Rheumatoid arthritis is the destructive disease that targets primarily joints. However, it also affects many other organs and systems, including brain, heart, kidneys, spleen, blood vessels, lungs, and muscles.

Rheumatoid arthritis affects around 1 in 100 people. In developed countries rheumatoid arthritis is the most common autoimmune disease. Though rheumatoid arthritis may start at any age, it is more common after sixty. One in twenty women over the age of 65 years suffers the disease. Economically it is very expensive disease. Besides high direct medical cost, there is much greater indirect medical price tag. Rheumatoid arthritis cause many complications, requires drastic therapies and orthopedic surgery. Doctors estimate that rheumatoid arthritis makes a one in-three patient permanently disabled. Half of the patients stop work in first decade of diagnosis.

Rheumatoid arthritis is a chronic disease. It leads to the loss of mobility due to joint destruction and pain. The joints suffer in a polyarticular manner. That means that many joints affected at the same time. Usually in the beginning joint problems are asymmetrical, later symmetrical ones. The pain improves when you use affected joints. Also there is the morning stiffness of all joints for an hour or more. In osteoarthritis pain worsens in opposite way - over the day after use.

Erosion and destruction of the joint surfaces eventually leads to deformity. The fingers are typically deviated towards the little finger and make unnatural shapes: boutonniere deformity, swan neck deformity, Z-Thumb, "squared hand. Besides joints problems patients suffer anemia, gastrointestinal bleeding from drugs, splenomegaly (big spleen) and leucopenia (Felty's syndrome), the salivary and lacrimal (tear) glands inflammation (Sjogren's syndrome).

Dermatological marks of rheumatoid arthritis include subcutaneous (under skin) nodules mostly on elbows. Lungs may get fibrosis and pulmonary effusions. Blood vessel disorders lead to nail fold infarcts, neuropathies and nephropathies. Amyloidosis affects kidneys, heart and muscles. Heart also suffers form pericarditis and valve destruction. Dry eyes, sclera inflammation and softening may be found. Fissure and leaking of eye humor could happen. Neurological system is affected by neuritis and atlanto-axial subluxation. Eventually it may lead to compression of the spinal cord, paralysis and quadriplegia.

To diagnose rheumatoid arthritis American College of Rheumatologists developed the criteria.

* Morning stiffness more than an hour
* Arthritis and soft-tissue swelling of more than 3 joints
* Arthritis of hand
* Symmetric arthritis
* Specific subcutaneous nodules
* High rheumatoid factor
* Radiological changes showing joint erosion

At least four criteria are needed to establish the diagnosis.

Immunological and other studies help to confirm the diagnosis: rheumatoid factor, anti-citrullinated protein antibodies, erythrocyte sedimentation rate, C-reactive protein, blood count, renal function tests, liver enzymes, antinuclear antibody. HLA marker DR4 is an important risk factor.