Why does the doctor look for warmth, swelling and tenderness?
Joints affected by arthritis often look swollen and feel warm and tender when the skin over the affected area is lightly touched. Although these factors can be present in other conditions, examining them closely provides your doctor with important clues. For example, fluid that builds up within a joint space can cause swelling that becomes firm when the joint is bent. This often occurs with rheumatoid arthritis, other inflammatory joint diseases, and sometimes even in osteoarthritis in the knee. In these cases, the doctor will often remove some of the fluid through a thin needle, using a process called aspiration. This allows the doctor to see if the fluid shows signs of inflammation, such as white blood cells, crystals, or signs of infection. On the other hand, when a joint appears swollen in osteoarthritis, it is usually due to bony growths or the widening of bones. The doctor can feel these by lightly squeezing the joint. Warm skin over the joint suggests that inflammation is presen
