Bicarbonate
Reflects the blood's main acid-base buffer; abnormal levels indicate metabolic or respiratory imbalance.
Typical reference range
| Range | Unit |
|---|---|
| 22–29 | mmol/l |
What Bicarbonate measures
Bicarbonate (sometimes reported as total CO2) reflects the blood's buffering system and overall acid-base balance. Bicarbonate is the main buffer that helps keep the blood from becoming too acidic or too alkaline, and its level is shaped by the interplay between the kidneys, which regulate it, and the lungs, which control carbon dioxide. It is usually measured as part of a metabolic panel alongside sodium, potassium, and chloride, so it is rarely read in isolation. A clinician interprets bicarbonate together with the other electrolytes and, when needed, the anion gap and measures of kidney and lung function, to understand what a result reflects about the body's balance.
What a high Bicarbonate can mean
A high bicarbonate level can reflect a metabolic alkalosis, a state in which the blood tends toward being too alkaline. Causes commonly associated with a raised level include prolonged vomiting or loss of stomach acid, some diuretics (water pills), and low potassium. A high bicarbonate can also appear when the body is compensating for a long-standing breathing-related (respiratory) acid-base change, holding on to bicarbonate to offset it.
When a shift is present, it may be linked with the underlying situation rather than symptoms from the bicarbonate itself, so the wider clinical picture matters. Bicarbonate is interpreted together with the other electrolytes, the anion gap where relevant, and how you are feeling. These results describe a pattern, not a diagnosis, and should be discussed with a clinician who can weigh them against your history and other findings.
What a low Bicarbonate can mean
A low bicarbonate level can reflect a metabolic acidosis, a state in which the blood tends toward being too acidic. Causes commonly associated with a low result include kidney conditions that reduce how well acid is cleared, uncontrolled diabetes with a build-up of acids (ketoacidosis), and severe diarrhea that causes loss of bicarbonate. A low level can also appear when the body is compensating for a breathing-related (respiratory) acid-base change.
Because different mechanisms can lower bicarbonate, a clinician interprets it alongside the anion gap, the other electrolytes, and kidney function to narrow down what is driving the result. Any linked symptoms usually stem from the underlying cause rather than the number itself. These results describe a pattern, not a diagnosis, and should be discussed with a clinician who can interpret them within the full picture and your history.
Track your Bicarbonate over time in Quanome — it reads your lab reports (PDF or photo) on your device, charts each marker against its range, and an AI coach explains what your trends mean alongside your Apple Health and DNA.