Toxins are substances created by plants and animals that are poisonous (toxic) to humans. Toxins may also include some medicines that are helpful in small doses, but poisonous in large amounts.
Most toxins that cause problems in humans come from germs such as bacteria. For example, the symptoms of cholera are caused by a toxin made by cholera bacteria.
Other toxins that may cause problems include metals, such as lead, and certain chemicals in the environment.
Lee WM. Toxin- and drug-induced liver disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 141.
Meehan TJ. Care of the poisoned patient. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 135.
Review Date 6/12/2023
Updated by: Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.