Gout and pseudo-gout: understanding the difference

Gout is caused by monosodium urate crystals, while pseudo-gout, also called calcium pyrophosphate deposition disease, is caused by calcium pyrophosphate crystals. Both can cause a sudden painful, warm and swollen joint. The knee and wrist are common sites for pseudo-gout; gout often affects the big toe but can involve the ankle or knee.

Symptoms overlap with infection and other inflammatory conditions. A high urate blood result alone does not prove that a particular attack is gout, and a normal result during an attack does not settle the question. Examination, history, imaging and analysis of fluid from the joint may all contribute.

Rest the affected joint, protect it from pressure and use a wrapped cool pack for short periods if comfortable. Contact a clinician promptly, particularly for a first attack, so treatment can match the cause and your kidney health and medicines. Do not take someone else's anti-inflammatory medicine or combine treatments without advice.

A suddenly hot, swollen joint with severe pain needs prompt assessment because infection can resemble crystal arthritis. Seek urgent help if fever, chills, confusion or marked illness occurs, or if you cannot move or use the limb. Repeated attacks also deserve review to reduce future joint damage and clarify the diagnosis.

Ask whether joint-fluid analysis, blood tests or imaging would help distinguish the conditions. Discuss which pain relief is safe with your kidney function and other medicines, and how to prevent another attack once the diagnosis is clear.