Fish Odor Syndrome: Symptoms & Signs

Medically Reviewed on 9/15/2020

Fish odor syndrome is a genetic disorder that results in an offensive body odor. Excessive excretion of trimethylamine (TMA) in the urine, sweat, and breath causes the symptoms. The condition has also been referred to as trimethylaminuria.

Symptoms of fish odor syndrome are primarily a fish-like odor in the sweat, urine, and breath of affected people. The intensity of the odor may vary over time. This strong body odor can interfere with many aspects of daily life, affecting a person's relationships and social life. Some affected people experience anxiety or depression as a result of the condition.

Cause of fish odor syndrome

Mutations in the FMO3 gene cause fish odor syndrome. In this condition, the body is unable to break down the compound trimethylamine that is present certain dietary proteins.

Other fish odor syndrome symptoms and signs

  • Fish-like Odor in the Breath, Sweat, and Urine

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.