What is metabolic acidosis?

Metabolic acidosis is a serious acid-base disorder that occurs when the body either produces too much acid, loses too much bicarbonate (an acid buffer), or can't effectively remove acid (via the kidneys), resulting in a lowered (acidic) blood pH.^[1]

Metabolic acidosis is sometimes called nonrespiratory acidosis or primary metabolic acidosis. Subtypes of metabolic acidosis like lactic acidosis and ketoacidosis have specific causes; however, these phrases are not exact synonyms for metabolic acidosis.^[1]

What causes metabolic acidosis?

Metabolic acidosis is a consequence of an underlying condition. Common causes include excessive acid production (e.g., in diabetic ketoacidosis),^[2] reduced acid excretion by the kidneys (e.g., in chronic kidney disease),^[3] or loss of bicarbonate (e.g., due to prolonged diarrhea).^[1]

Metabolic acidosis exists in two forms: acute metabolic acidosis (lasting minutes to days) and chronic metabolic acidosis (lasting weeks to years).^[1] Acute forms typically result from the overproduction of acids like ketoacids or lactic acid, while chronic forms are often caused by kidney dysfunction and impaired acid elimination.^[1]

What are the symptoms of metabolic acidosis?

Symptoms of metabolic acidosis can include fatigue, rapid breathing, and confusion. Severe cases can damage organs if not treated promptly.^[1] However, the effects vary by type. For example, acute metabolic acidosis primarily impacts cardiovascular function (decreased cardiac output, low blood pressure, and heart arrhythmias) whereas chronic metabolic acidosis affects muscle (skeletal muscle atrophy) and bone health (abnormal bone metabolism).^[1]

How is metabolic acidosis diagnosed?

Metabolic acidosis is diagnosed using blood tests that measure pH, bicarbonate, and other chemical markers like sodium and chloride.^[1]

How is metabolic acidosis treated?

Because metabolic acidosis is a consequence of an underlying condition, its treatment depends on the underlying cause and, therefore, may include medications, intravenous fluids, or specific therapies (such as insulin for diabetic ketoacidosis).^{[4][2][1][5][6]} Correcting the acid-base imbalance helps restore normal body function and prevents complications.^[1][5][6]

Sodium bicarbonate is sometimes used to treat metabolic acidosis; however, while it is effective for treating chronic metabolic acidosis, its use in acute metabolic acidosis is controversial because of its variable efficacy and potential adverse effects.^{[7][8][1][5][6]}