Arthritis

Arthritis (from Greek arthro-, joint + -itis, inflammation) is a group of conditions that affect the health of the bone joints in the body. One in three adult Americans suffer from some form of arthritis and the disease affects about twice as many women as men.

Arthritic diseases include psoriatic and rheumatoid arthritis, which are autoimmune diseases; septic arthritis, caused by joint infection; and the more common osteoarthritis, or degenerative joint disease, which can be caused from strains and injuries caused by repetitive motion, sports, overexertion, and falls. Unlike the autoimmune diseases, osteoarthritis largely affects older people and results from the degeneration of joint cartilage.

Arthritic joints can be sensitive to weather changes. The increased sensitivity is thought to be caused by the affected joints developing extra nerve endings in an attempt to protect the joint from further damage.

All arthritis features pain, which is generally worse in the morning and on initiating movement, and resolves in the cause of time. In elderly people and children, the pain may not be the main feature, and the patient simply moves less (elderly) or refuse to use the affected limb (children).

When faced with joint pain, a doctor will generally ask about several other medical symptoms (such as fever, skin symptoms, breathlessness, Raynaud's phenomenon) that may narrow down the differential diagnosis to a few items, for which testing can be done.

Arthritis and fever together are pointers towards septic arthritis (see below). This is a medical emergency, and requires urgent referral to a rheumatologist.

The various types of arthritis can be distinguished by the pace of onset, the age and sex of the patient, the amount of (and which) joints affected, additional symptoms (such as psoriasis, iridocyclitis, Raynaud's phenomenon, and rheumatoid nodules), and other clues.

Blood tests and X-rays of the affected joints are often performed to make the diagnosis. X-rays can show erosions or bone appositions.