Diseases & Conditions

Acidosis, Metabolic - Metabolic Acidosis


Overview, Causes, & Risk Factors

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.

What is going on in the body?

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.

What are the causes and risks of the disease?

Metabolic acidosis can be caused by many different situations, including:

  • some types of kidney disease or kidney failure
  • an overdose of aspirin
  • ingestion of ethylene glycol, a chemical found in antifreeze
  • shock, a condition that occurs in very sick people due to poor blood flow throughout the body
  • diabetic ketoacidosis, a condition that occurs in certain people with uncontrolled type 1 diabetes mellitus
  • medications, such as a diuretic or "fluid pill" called acetazolamide. A diabetes medication called metformin occasionally causes metabolic acidosis.
  • severe diarrhea
  • Other causes are also possible.


    Symptoms & Signs

    What are the signs and symptoms of the disease?

    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:

  • weakness
  • confusion
  • shock
  • heart problems such as arrhythmias
  • If the metabolic acidosis is not effectively treated, it can lead to death.


    Diagnosis & Tests

    How is the disease diagnosed?

    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.


    Prevention & Expectations

    What can be done to prevent the disease?

    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.

    What are the long-term effects of the disease?

    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.

    What are the risks to others?

    Metabolic acidosis is not contagious and does not put other people at risk.


    Treatment & Monitoring

    What are the treatments for the disease?

    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.

    What are the side effects of the treatments?

    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.

    What happens after treatment for the disease?

    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.

    How is the disease monitored?

    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.


    Attribution

    Author:Adam Brochert, MD
    Date Written:
    Editor:Coltrera, Francesca, BA
    Edit Date:04/21/00
    Reviewer:Melissa Sanders, PharmD
    Date Reviewed:07/05/01

    Sources

    Harrison's Principles of Internal Medicine, 1998, Fauci et al.