Hypoxemia is a medical condition characterized by low levels of oxygen in the blood. It can occur due to various factors, including respiratory diseases, heart problems, or high altitudes. When oxygen levels drop, the body's organs and tissues may not receive enough oxygen to function properly, leading to symptoms like shortness of breath, confusion, or fatigue. Diagnosis of hypoxemia typically involves measuring blood oxygen levels using a pulse oximeter or arterial blood gas test. Treatment may include supplemental oxygen therapy or addressing the underlying cause, such as managing a lung disease or improving circulation.