Lactic acidosis is when lactic acid builds ups in the blood stream faster than it can be removed. Lactic acid is produced when oxygen levels in the body drop.
The most common cause is intensive exercise. However, it can also be caused by certain diseases, such as sepsis, respiratory failure, AIDS, cancer, and kidney failure.
Metformin, a common medicine used to treat diabetes, can also cause lactic acidosis. Persons who take this medicine should have their electrolyte levels checked 1 - 2 weeks after starting it.