Pseudogout is a type of arthritis that causes pain, redness, heat, and swelling in many joints, symptoms that resemble those of gout. Unlike gout, though, the symptoms of pseudogout are caused by deposits of tiny crystals of calcium pyrophosphate dihydrate rather than uric acid.

In pseudogout, the joint most often affected is the knee. Over time, pseudogout may damage the cartilage of the joint. As this happens, the bones rub together and cause joint pain. Pseudogout usually affects people in their 60s and is rarely seen in people younger than 30.

Pseudogout usually can be relieved with treatment, which may involve steroid medicines (either oral or injected), aspirating the joint to relieve pressure, or taking colchicine medicine. Nonsteroidal anti-inflammatory medications (NSAIDs) may help ease painful attacks.