Arterial Blood Gas (ABG) is a medical test that measures the levels of oxygen, carbon dioxide, and acidity (pH) in the blood. It is typically performed on blood drawn from an artery, usually in the wrist. This test helps assess how well the lungs and kidneys are functioning and can indicate respiratory or metabolic issues. The results of an ABG can provide critical information about a patient's respiratory status, such as hypoxemia (low oxygen levels) or hypercapnia (high carbon dioxide levels). Healthcare providers use this data to guide treatment decisions for conditions like asthma, COPD, or kidney disease.