Blood gases are gaseous components present in the blood, primarily oxygen (O₂), carbon dioxide (CO₂), and blood pH. They are measured to evaluate respiratory function, acid-base balance, and the effectiveness of gas exchange in the lungs. This test is crucial for detecting respiratory and metabolic problems.

The blood gases test is performed by drawing a blood sample, usually from an artery, though sometimes it may be taken from a vein. The procedure may be slightly more uncomfortable than a venous blood draw due to arterial pressure, but it is quick and provides valuable information about lung function.

The blood gas test results include oxygen levels, carbon dioxide levels, and pH. Low oxygen levels can indicate respiratory problems, while high carbon dioxide levels may suggest hypoventilation. A pH outside the normal range can indicate acidosis or alkalosis, which requires further evaluation.

Generally, no special preparation is required for the blood gas test. However, your doctor may ask you to avoid smoking or intense exercise before the test to ensure more accurate results. Make sure to inform your doctor about any medications you are taking, as some can affect the results.