Blood oxygen is one of the key indicators of human health. Blood oxygen saturation (SpO₂) refers to the concentration of oxygen in the blood and is a critical physiological parameter of the body's respiratory and circulatory system. By using a pulse oximeter, individuals can monitor their current physical condition.

In general:

94% – 100% indicates normal, healthy oxygen levels.

90% – 94% indicates mild hypoxia (low oxygen).

Below 90% indicates severe hypoxia.

A level below 80% may lead to impaired heart and brain function.