Conditions with Similar Symptoms
Numerous conditions have symptoms of joint aches and pains. Something as benign as sleeping on a bad mattress to the serious afflictions associated with cancer can mirror symptoms of osteoarthritis. Other problems that can cause aches and pains in the joints include physical injuries, infections, tendinitis, and poor circulation. A number of rare genetic diseases attack the joints.
Osteoarthritis can generally be distinguished from other joint diseases by considering several factors together:
- Osteoarthritis usually occurs in older people and is located in only one or a few joints
- The joints are less inflamed than in other arthritic conditions
- Progression of pain is usually gradual.
A few of the most common disorders that can be confused with, or may even accompany, osteoarthritis are discussed below.
Rheumatoid Arthritis
Osteoarthritis may be confused with rheumatoid arthritis, particularly when osteoarthritis affects multiple joints in the body. Rheumatoid arthritis begins in the synovial membrane rather than the cartilage. It normally occurs earlier in life than osteoarthritis, often striking people in their 30s and 40s. Rheumatoid arthritis many joints, and often occurs symmetrically on both sides of the body. People generally have morning stiffness that lasts for at least an hour. (Stiffness from osteoarthritis usually clears up within half an hour.)
X-rays show changes in the bones that differ from those occurring in osteoarthritis. In rheumatoid arthritis, blood tests often show a specific antibody, known as rheumatoid factor, which is not present with osteoarthritis. In another blood test, levels of a factor called erythrocyte sedimentation rate (ESR) are often elevated in rheumatoid arthritis, but they are generally normal in osteoarthritis. Rheumatoid arthritis also does not usually show up in the fingertips where osteoarthritis is common.

Chondrocalcinosis
Chondrocalcinosis is a disease in which certain calcium crystals known as CPPD (calcium pyrophosphate dihydrate) are deposited in the joints. It affects about 25% of the population and can accompany and even worsen osteoarthritis. The problem has been called pseudogout or pseudo-osteoarthritis, in the latter case particularly when it affects the knees. A doctor can usually differentiate between the two disorders, however, because chondrocalcinosis usually damages other joints (such as wrists, elbows, and shoulders) that are not usually affected by osteoarthritis. The condition may explain why some patients with osteoarthritis receive benefit from colchicine, a drug used for gout and other crystal-induced joint diseases.
Charcot's Joint
Charcot's joint occurs when an underlying disease, usually diabetes, causes nerve damage in the joint, which leads to swelling, bleeding, increased temperature, and changes in bone. There may be a loss of sensation that leads to an increased risk for injury from overuse.


