Gout and pseudogout are crystal-induced arthropathies caused by the deposition of urate crystals or calcium pyrophosphate dihydrate crystals in the joints respectively. Gout results in painful flares typically affecting the big toe and is characterized by periods of acute inflammation. Pseudogout causes intermittent arthritis that may be asymptomatic and is detected by chondrocalcinosis on x-rays. Both can be diagnosed by identifying the characteristic crystals in synovial fluid under polarized microscopy. Treatment involves management of symptoms during acute flares and reducing crystal deposition long-term.