What is metabolic acidosis?
Metabolic acidosis is a condition where the blood is more acidic than it should be.
This page provides additional information on metabolic acidosis for patients who have been diagnosed with this condition by their doctor.
What are the causes of metabolic acidosis?
Metabolic acidosis has several causes which include:
- Kidney failure: the kidneys remove certain acids from the body in the urine. They also prevent too much bicarbonate (a naturally occurring chemical called an electrolyte), which decreases acidity, being lost in the urine.
- Type 1 diabetes mellitus: if severe this can cause diabetic ketoacidosis, where cells use fats instead of sugars for energy, which increases production of certain acids called ketoacids.
- Lactic acidosis: this is where the body tissues don’t receive enough oxygen, so cells change the way they use energy, which produces acids. This can be caused by severe illness, such as heart failure, or certain drugs and toxins.
- Ingestion of certain toxic chemicals, such as ethylene glycol, found in poisonous products such as antifreeze.
- Severe diarrhoea: quicker movement of ingested material through the gut means less bicarbonate can be reabsorbed into the body.
Metabolic acidosis symptoms and signs
Symptoms depend on the cause of the metabolic acidosis. Mild metabolic acidosis symptoms can include:
- Being tired
- Feeling and/or being sick
If metabolic acidosis worsens symptoms can include:
- Changes in breathing: usually deeper breathing, which can also be faster than normal.
- Feeling very weak
- Drowsiness
- Confusion
- Feeling increasingly sick
- Fast heart rate
- Dizziness
Severe metabolic acidosis usually occurs in the context of a severe illness, such as sepsis, and can cause heart and blood pressure problems and lead to a coma.
It is important you seek medical advice, and urgent medical attention where appropriate, if you are concerned about your health.
Diagnosis of metabolic acidosis
Metabolic acidosis is normally diagnosed with a blood test. The acidity of the blood is measured and the levels of certain chemicals and electrolytes, including bicarbonate.
Further tests may be needed to look for the cause of the metabolic acidosis, such as urine tests or medical images.
How is metabolic acidosis treated?
Once the cause of the metabolic acidosis is identified this is treated.
If you have later stage chronic kidney disease (CKD), and have metabolic acidosis, you may be given sodium bicarbonate tablets by your doctor. Bicarbonate is a substance naturally found in the body that helps neutralise acid.
Patients on dialysis usually have acidosis, which is treated by adding bicarbonate in the dialysis fluid.
References
Berman, J. Metabolic acidosis [online]. Medlineplus.gov, USA; Nov 2023 [Accessed 19 September 25]. Available from: Metabolic acidosis: MedlinePlus Medical Encyclopedia
Lewis, J. Metabolic Acidosis [online]. MSD Manual, Merck & Co, Inc., Rahway, NJ, USA; Mar 2025 [Accessed 19 September 25]. Available from: Metabolic Acidosis - Endocrine and Metabolic Disorders - MSD Manual Professional Edition
Hazell, T. Metabolic acidosis [online]. Patient.info, Navigate Health Ltd: London, UK; Jun 2022 [Accessed 19 September 25]. Available from: Metabolic Acidosis (Causes, Symptoms, and Treatment)
NICE [online]. Nice.org, England;[Accessed 19 September 25]. Available from: Fluids and electrolytes | Treatment summaries | BNF | NICE
Lewis, J. Acidosis [online]. MSD Manual, Merck & Co, Inc., Rahway, NJ, USA; Feb 2026 [Accessed 13 February 26]. Available from: Acidosis - Hormonal and Metabolic Disorders - MSD Manual Consumer Version
Reviewed March 2026 by Professor Simon Davies.
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