Hypoxia

decrease below normal levels of oxygen in inspired gases, arterial blood, or tissue

Description
Hypoxia may have diverse causes, such as anemia, high altitude, airway obstruction or ischemia (blood vessel occlusion). Patients with sickle cell disease must be monitored for hypoxia when hospitalized, by measuring the oxygen saturation of hemoglobin in the blood with a pulse oximeter or by examining blood gases. The oxygen saturation of the blood is given as a percentage (normally approximately 96%) of total saturation and is referred to as SpO2, with the S standing for saturation.