Acidosis is a condition in which there is too much acid in the body fluids. It is the opposite of alkalosis (a condition in which there is too much base in the body fluids).

Causes, incidence, and risk factors

The kidneys and lungs maintain the balance (proper pH level) of chemicals called acids and bases in the body. Acidosis occurs when acid builds up or when bicarbonate (a base) is lost. Acidosis is classified as either respiratory acidosis or metabolic acidosis.

Respiratory acidosis develops when there is too much carbon dioxide (an acid) in the body. This type of acidosis is usually caused when the body is unable to remove enough carbon dioxide through breathing. Other names for respiratory acidosis are hypercapnic acidosis and carbon dioxide acidosis. Causes of respiratory acidosis include:

Chest deformities, such as kyphosis

Chest injuries

Chest muscle weakness

Chronic lung disease

Overuse of sedative drugs

Metabolic acidosis develops when too much acid is produced or the kidneys cannot remove enough acid from the body. There are several types of metabolic acidosis:

Diabetic acidosis (also called diabetic ketoacidosis and DKA) develops when substances called ketone bodies (which are acidic) build up during uncontrolled diabetes.

Hyperchloremic acidosis is caused by the loss of too much sodium bicarbonate from the body, which can happen with severe diarrhea.

Lactic acidosis is a buildup of lactic acid. This can be caused by:



Exercising vigorously for a very long time

Liver failure

Low blood sugar (hypoglycemia)

Medications such as salicylates

MELAS (a rare genetic disorder that affects energy production)

Prolonged lack of oxygen from shock, heart failure, or severe anemia


Other causes of metabolic acidosis include:

Kidney disease (distal renal tubular acidosis and proximal renal tubular acidosis)

Poisoning by aspirin, ethylene glycol (found in antifreeze), or methanol

Severe dehydration



Metabolic acidosis

Respiratory acidosis

Signs and tests

An arterial blood gas analysis or serum electrolytes test, such as a basic metabolic panel, will confirm that acidosis is present and indicate whether it is metabolic acidosis or respiratory acidosis. Other tests may be needed to determine the cause of the acidosis.


Treatment depends on the cause.

Expectations (prognosis)

Acidosis can be dangerous if untreated. Many cases respond well to treatment.


Complications depend on the specific type of acidosis.

Calling your health care provider

Although there are several types of acidosis, all will cause symptoms that require treatment by your health care provider.


Prevention depends on the cause of the acidosis. Normally, people with healthy kidneys and lungs do not experience significant acidosis.