Usually as part of a renal profile (collection of tests which help investigate kidney function), to screen for an electrolyte or acid-base imbalance in conditions known to cause such disturbances or to monitor a known imbalance
Bicarbonate
May be part of a routine blood test that includes electrolyte measurements or may be requested by your doctor if you have a medical condition or are experiencing symptoms that could indicate problems with the acid-base balance of your body
A blood sample taken from a vein in the arm
None
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How is it used?
Bicarbonate levels are usually measured with other electrolytes to tell your doctor whether your sodium, potassium, chloride, and bicarbonate levels are in balance. They may be measured as part of routine blood testing, or when your doctor suspects an imbalance. Bicarbonate may also be measured when your doctor is evaluating your acid-base balance, to screen for an imbalance, and to monitor a known problem during treatment.
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When is it requested?
Bicarbonate testing may be requested, usually as part of an electrolyte profile when:
- you are having a routine blood test;
- your doctor suspects that water imbalance is upsetting your electrolyte balance;
- to help evaluate your acid-base balance (pH);
- to monitor a condition or treatment that might cause an electrolyte imbalance.
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What does the test result mean?
When bicarbonate levels are higher or lower than normal, it suggests that your body is having trouble maintaining its acid-base balance either by failing to remove carbon dioxide or perhaps because of an electrolyte imbalance, particularly a deficiency of potassium. Both of these imbalances may be due to a wide range of dysfunctions.
Some of the causes of a low bicarbonate level include:
- A hormone disorder such as Addison disease
- Chronic diarrhoea
- Diabetic ketoacidosis
- Metabolic acidosis
- Kidney disease
- Alcohol poisoning
- Salicylate (aspirin) overdose
Increased levels may be due to:
- Severe vomiting
- Lung diseases, including chronic obstructive pulmonary disease (COPD)
- Hormone disorders such as Cushing or Conn syndrome
- Metabolic alkalosis
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Is there anything else I should know?
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If bicarbonate levels are too high or low, what treatments can help?
If your bicarbonate is high or low, your doctor will identify and treat the underlying cause. For example, high bicarbonate may be caused by emphysema (which may be treated with oxygen therapy and drugs), or by severe diarrhoea or vomiting (which would be treated by treating the reason for the diarrhoea or vomiting). Low bicarbonate may be caused by, for example, diabetic ketoacidosis, which can be treated in part by correcting the blood sugar (glucose) problem that led to the ketoacidosis.
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What other gases circulate in blood?
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If my doctor has measured bicarbonate, why do they want to do blood gases?
Blood gas tests, in which blood is taken from an artery instead of a vein, can give your doctor a better assessment of your acid-base status and indicate whether you are taking in enough oxygen and getting rid of enough CO2.