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).
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 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 in the body. It can also occur when 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.
- Kidney disease (distal renal tubular acidosis and proximal renal tubular acidosis)
- Poisoning by aspirin, ethylene glycol (found in antifreeze), or methanol
- Severe dehydration
Lactic acidosis is a buildup of lactic acid. Lactic acid is mainly produced in muscle cells and red blood cells. It forms when the body breaks down carbohydrates to use for energy when oxygen levels are low. This can be caused by:
- Drinking too much alcohol
- Exercising vigorously for a very long time
- Liver failure
- Low blood sugar (hypoglycemia)
- Medications, such as salicylates
- MELAS (a very rare genetic mitochondrial disorder that affects energy production)
- Prolonged lack of oxygen from shock, heart failure, or severe anemia
- Sepsis -- severe illness due to infection with bacteria or other germs
Metabolic acidosis symptoms depend on the underlying disease or condition. Metabolic acidosis itself usually causes rapid breathing. Confusion or lethargy may also occur. Severe metabolic acidosis can lead to shock or death.
Respiratory acidosis symptoms can include confusion, fatigue, lethargy, shortness of breath, and sleepiness.
Exams and Tests
The health care provider will perform a physical examination and ask about your symptoms.
Laboratory tests that may be ordered include:
- Arterial blood gas analysis
- Electrolytes test, such as a basic metabolic panel to confirm acidosis and show whether it is metabolic or respiratory acidosis.
Other tests may be needed to determine the cause of the acidosis.
Treatment depends on the cause. Your provider will tell you more.
Acidosis can be dangerous if untreated. Many cases respond well to treatment.
Complications depend on the specific type of acidosis.
When to Contact a Medical Professional
All the types of acidosis will cause symptoms that require treatment by your provider.
Prevention depends on the cause of the acidosis. Many causes of metabolic acidosis can be prevented, including diabetic ketoacidosis and some causes of lactic acidosis. Normally, people with healthy kidneys and lungs do not have serious acidosis.
Gaw A, Murphy MJ, Srivastava R, Cowan RA, O'Reilly DS. Acid-base disorders. Gaw A, Murphy MJ, Srivastava R, Cowan RA, O'Reilly DS, eds. Clinical Biochemistry: An Illustrated Colour Text. 5th ed. Philadelphia: PA: Elsevier; 2013:chap 24.
Strayer RJ. Acid-base disorders. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Mosby; 2014:chap 124.
Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.