Hypoxemia, or low blood oxygen, describes a lower than normal level of oxygen in your blood. In order to function properly, your body needs a certain level of oxygen circulating in the blood to cells and tissues. When this level of oxygen falls below a certain amount, hypoxemia occurs and you may experience shortness of breath.
Your doctor determines whether you have hypoxemia by measuring your blood oxygen level — the amount of oxygen traveling in your arteries. Your blood oxygen can be measured by testing a sample of blood from an artery.
An approximate blood oxygen level can also be estimated using a pulse oximeter — a small device that clips on your finger. Though the pulse oximeter actually measures the saturation of oxygen in your blood, the results are often used as an estimate of blood oxygen levels. Normal pulse oximeter readings range from 95 to 100 percent, under most circumstances. Values under 90 percent are considered low.
- A blocked airway
- ARDS (acute respiratory distress syndrome)
- Certain medications, such as narcotics and anesthetics, which depress breathing
- Congenital heart disease — heart defects that are present at birth
- COPD (chronic obstructive pulmonary disease)
- High altitudes
- Interstitial lung disease
- Pulmonary edema
- Pulmonary embolism
- Pulmonary fibrosis
- Sleep apnea
Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.