Lactic acidosis: Acidosis (too much acid in the body) due to the buildup of lactic acid in the body. Lactic acidosis occurs when cells make lactic acid (from glucose) faster than it can be metabolized. The key signs of lactic acidosis include unusually deep and rapid breathing, vomiting, and abdominal pain.
Lactic acidosis is a feature of different disorders, usually indicating a metabolic derangement in the acid-base system of the body. Sometimes associated with severe infection, and can be a rare side effect of some medications such as metformin (Glucophage).