Metabolic acidosis is a condition in which the acid level within the blood is higher than normal. By definition, the condition is not due to breathing problems, which is known as respiratory acidosis.
The lungs and kidneys help control the amount of acid in the blood. These two organs work hard to keep a normal level of acid in the blood. Certain non-lung diseases and conditions, when severe, can overwhelm the kidneys. Alternatively, the kidneys themselves may not work. Either of these situations can cause high acid levels in the blood, or metabolic acidosis.
Metabolic acidosis can be caused by many different situations, including:
Other causes are also possible.
In many cases, there are no symptoms from the metabolic acidosis. Often, there may be symptoms related to the underlying medical problem that has lead to the metabolic acidosis. If metabolic acidosis becomes severe, the person may develop:
If the metabolic acidosis is not effectively treated, it can lead to death.
Metabolic acidosis may be suspected after a history and physical exam. The diagnosis is often confirmed with a blood test called arterial blood gases. This test will demonstrate an increased level of acid within the blood, and may help figure out the cause.
Further tests may also be needed to diagnose the underlying problem. For example, a blood glucose test can help diagnose diabetes. Blood tests known as the BUN and creatinine level can help diagnose kidney failure. Other tests are also possible.
Metabolic acidosis often cannot be prevented. Medications should be taken as prescribed. Those with diabetes should check their blood sugar levels regularly. Antifreeze and other harmful chemicals should be kept out of the reach of young children. Those with diarrhea should drink a lot of fluids to avoid dehydration.
Most people recover fully once the cause of the metabolic acidosis is treated, and have no long-term effects. Severe acidosis may result in coma or death if not corrected.
Metabolic acidosis is not contagious and does not put other people at risk.
The main goal of treatment is to correct the underlying problem that created the metabolic acidosis. Once the cause is treated, the body will naturally correct the acid level. For example, someone with diabetic ketoacidosis needs insulin, a natural hormone that can be given as a medication to lower the blood sugar level. Those who have shock due to a severe infection may need antibiotics or surgery. In some cases, dialysis is required. Dialysis is a procedure to filter the blood. It is usually done when the kidneys fail or after a severe drug overdose.
All medications have possible side effects. For example, antibiotics may causallergic reactions and stomach upset. Other side effects may occur and depend on the medications used. Dialysis carries a risk for low blood pressure, infection and other problems. Surgery carries a risk of bleeding and infection.
If the underlying cause of the metabolic acidosis can be treated, the acid levels in the body usually return to normal. In these cases, no further treatment may be needed. Those with permanent kidney failure may need dialysis for the rest of their lives.
Repeated blood tests can be done to follow the acid level in the blood if needed. Other monitoring relates to the cause. For example, someone with diabetes needs to monitor his or her blood sugar levels regularly for life. Any new or worsening symptoms should be reported to the healthcare provider.
Author:Adam Brochert, MD
Date Written:
Editor:Coltrera, Francesca, BA
Edit Date:04/21/00
Reviewer:Melissa Sanders, PharmD
Date Reviewed:07/05/01
Harrison's Principles of Internal Medicine, 1998, Fauci et al.