Bicarbonate
Bicarbonate / total CO₂: reflects acid–base balance in blood.
What it is
Often reported as total CO₂ or bicarbonate in mmol/L on a biochemistry panel.
Blood bicarbonate (often labelled total CO₂ on venous biochemistry) reflects the metabolic component of acid–base balance. Reported in mmol/L. Arterial blood gases are used when precise acid–base assessment is needed in acute care.
Blood bicarbonate (often labelled total CO₂ on venous biochemistry) reflects the metabolic component of acid–base balance. Reported in mmol/L. Arterial blood gases are used when precise acid–base assessment is needed in acute care.
Why it matters
Low or high values can relate to kidney, lung, or metabolic issues, vomiting/diarrhoea, or sample delays. Marked acid–base disturbance is clinical territory, seek care for severe weakness, confusion, or breathing change.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
Low bicarbonate can indicate metabolic acidosis (kidney disease, diabetic ketoacidosis, losses, toxins); high values can indicate metabolic alkalosis (vomiting, diuretics) or compensation for lung disease. Sample delays and tourniquet time can affect results. Marked abnormalities with breathing change, confusion, or severe vomiting need urgent care.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
Low bicarbonate can indicate metabolic acidosis (kidney disease, diabetic ketoacidosis, losses, toxins); high values can indicate metabolic alkalosis (vomiting, diuretics) or compensation for lung disease. Sample delays and tourniquet time can affect results. Marked abnormalities with breathing change, confusion, or severe vomiting need urgent care.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
How it affects the body
Bicarbonate buffers acids from metabolism. Lungs and kidneys defend pH; blood bicarbonate hints at how that defence is coping.
The bicarbonate buffer system partners with lung CO₂ exhalation and kidney acid excretion to keep pH compatible with enzyme function. Cells generate acid continuously from metabolism; buffers buy time for lungs and kidneys to finish the job.
The bicarbonate buffer system partners with lung CO₂ exhalation and kidney acid excretion to keep pH compatible with enzyme function. Cells generate acid continuously from metabolism; buffers buy time for lungs and kidneys to finish the job.
For athletes
Sprint and combat sports sometimes discuss buffering, but blood bicarbonate on a random panel is not a training target to manipulate without medical supervision.
High-intensity sport produces lactic acid transiently; venous bicarbonate on a rested panel is not a training adaptation score. Do not use baking-soda loading protocols without understanding GI and race-day risks, and never to “correct” a lab value.
High-intensity sport produces lactic acid transiently; venous bicarbonate on a rested panel is not a training adaptation score. Do not use baking-soda loading protocols without understanding GI and race-day risks, and never to “correct” a lab value.
Related tests
No published panels currently list this marker.