Pseudogout, also called calcium pyrophosphate deposition disease, is a type of arthritis that causes painful swelling in one or more joints, according to Mayo Clinic. The onset of pseudogout is rapid, and the pain and swelling it causes often lasts for weeks.
The condition gets its name due to its similarities to gout, notes Mayo Clinic. Crystal deposits in the joints cause both gout and pseudogout, but the crystals are not the same. The cause of pseudogout is unclear to medical science. The condition can occur in any joint, but the knees are most commonly affected. Pseudogout less commonly affects the ankles and wrists.