partial pressure of oxygen (pO2)

Partial pressure of oxygen (pO₂) refers to the measure of oxygen’s pressure within a mixture of gases, such as air, indicating how much oxygen is present. It reflects the concentration of oxygen available to tissues and is measured in units called millimeters of mercury (mmHg). Essentially, pO₂ shows how effectively oxygen can move from the lungs into the blood and then to the body's cells. Higher pO₂ means more oxygen is available, while lower pO₂ indicates less oxygen, which can impact body function and health.