Calcium pyrophosphate deposition (CPPD)

A condition in which calcium pyrophosphate crystals collect in joint cartilage. It can cause sudden painful joint swelling or long-term arthritis that resembles osteoarthritis. Finding crystals in fluid drawn from the joint confirms the diagnosis; doctors also consider symptoms and imaging. Older age, osteoarthritis, an overactive parathyroid gland, haemochromatosis and low magnesium make it more likely.

Related terms

• Condition

  Haemochromatosis

  An inherited condition in which the body stores too much iron. Its joint disease typically affects the knuckle joints of the index and middle fingers, often years before diagnosis. Blood tests (transferrin saturation and ferritin) are the first step. Removing iron by regular blood draws protects the liver and other organs, but established joint changes often do not improve.

Articles mentioning this term

1. Patient information · 11 October 2026

   Knuckle joint arthritis

   Knuckle (MCP) joint pain and swelling: causes beyond osteoarthritis, tests, warning signs, non-surgical care and joint replacement.

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