by Scholten A


Hypoxemia is a low level of oxygen in the blood. It lowers the amount of oxygen that reaches organs like the heart, kidney, and brain. It can be mild or severe. When severe it can affect heart and brain function.


Hypoxemia may be caused by:

  • Problems getting oxygen into the lungs—such as with asthma
  • Trouble moving oxygen from the lungs to the blood—such as with lung damage or disease

Risk Factors

Things that raise the risk of hypoxemia are:

  • Heart or lung problems
  • Sleep apnea
  • Places with high altitude
  • Taking certain medicines


Symptoms of hypoxemia may be:

  • Headache
  • Fast breathing
  • Fast heartbeats
  • Restlessness
  • Confusion


The doctor will ask about symptoms and past health. A physical exam will be done. Some signs like blue-ish nails or skin may mean low oxygen levels.

Oxygen levels can be tested with:

  • Pulse oximetry—a sensor placed on the finger
  • Blood tests

Breathing tests may also be done to check how well the lungs work.


The goal is to raise oxygen levels in the blood. Some may need emergency care right away. Others may need a change in their care plan.

The main treatment will be oxygen therapy. Oxygen may be given through a mask or a tube just under the nose. Oxygen may be needed:

  • Short term—until problems have passed
  • Long term and daily—for conditions like COPD


Not all hypoxemia can be prevented. Some people are at risk due to certain conditions. They may reduce their risk by following their care plan.


American Lung Association  

Centers for Disease Control and Prevention 


College of Family Physicians of Canada 

Health Canada 


Hypoxemia—approach to the patient. EBSCO DynaMed website. Available at: Accessed August 5, 2021.

Hypoxemia. Cleveland Clinic website. Available at: Accessed August 5, 2021.

Luks AM, Swenson ER, et al. Acute high-altitude sickness. Eur Respir Rev. 2017;26(143):160096.

Revision Information

  • Reviewer: EBSCO Medical Review Board Dan Ostrovsky, MD
  • Review Date: 07/2021
  • Update Date: 08/05/2021