lactic acid
Meaning of lactic acid: Lactic acid is produced naturally in muscle and other tissue during energy metabolism and is also formed by bacteria that ferment food and skin products.
Definition of lactic acid
Lactic acid is a compound produced naturally within the body, particularly in muscle tissue, as part of energy metabolism when cells generate energy without using enough oxygen, a process that becomes more prominent during intense physical exertion. It is also produced outside the body by certain bacteria that ferment sugars, a process used to make foods such as yogurt and sourdough bread.
In the bloodstream, lactic acid exists mostly in its ionized form, called lactate, and blood lactate levels are measured clinically as a marker of how tissues are metabolizing oxygen, with notably elevated levels seen in conditions such as severe infection or reduced blood flow to tissue.
Lactic acid is also used commercially as a type of alpha hydroxy acid in skin care products, where it is applied to exfoliate the outer layer of skin, and it belongs to a broader category of related acids used for similar cosmetic purposes.
Also known as
Used in a sentence
A blood lactate level was checked to help evaluate the patient's tissue oxygenation during the acute illness.
Good to know
What is measured on a blood test is technically lactate, the ionized form of lactic acid circulating in blood, though the two terms are often used interchangeably in casual discussion.
Word origin
Where “lactic acid” comes from
Formed from Latin lac, lactis, meaning milk, since the compound was first identified in soured milk.