Bicarbonate (HCO₃⁻) concentration in blood

What Does This Test Measure?

Bicarbonate is a critical buffer in your blood, working alongside carbon dioxide and oxygen to keep your body’s acidity within a narrow, healthy range. Your kidneys and lungs work together to regulate bicarbonate levels, but this test specifically checks the amount present in your bloodstream. Low or high levels can signal underlying health issues, such as metabolic or respiratory disorders.

Why Might You Need This Test?

Doctors may order a bicarbonate test to diagnose or monitor conditions like kidney disease, diabetes, heart failure, or respiratory problems. It can also help assess how well your body is handling acid-base imbalances, especially after treatments like dialysis or certain medications.

What Does a Result Mean?

While exact reference ranges vary by lab, abnormal bicarbonate levels can indicate acid-base disorders. For example, low bicarbonate (metabolic acidosis) may occur with kidney problems or excessive vomiting, while high levels (metabolic alkalosis) could be linked to conditions like severe dehydration or overuse of antacids.

How Is This Test Done?

This test typically involves drawing blood from a vein in your arm. The sample is sent to a lab where bicarbonate concentration is measured using an automated method, often part of a broader blood gas analysis that also checks oxygen, carbon dioxide, and pH levels.