Hypoxemia is a condition in which there is a low partial oxygen pressure in the blood of the arteries. Among the causes of hypoxemia are lack of oxygen concentration in the environment, airway blockages, heart disorders, lung problems and sleep apnea. Certain medications, such as aesthetics and narcotics, also produce low arterial blood pressure. Hypoxemia is often a serious problem that requires medical attention.
The air that is present at extremely high altitudes has a reduced oxygen concentration. A person who breathes in this air can develop hypoxemia because of this oxygen desaturation. The alveoli of the lungs do not receive the required amount of oxygen when the barometric pressure is low because of the heightened elevation.
![](http://images.wisegeek.com/slideshow-mobile-small/man-with-sleep-apnea-with-machine.jpg)
Blockages of a person's airway is one of the causes of hypoxemia because there is not enough oxygen delivered to the body’s cells. A blockage can be caused by choking on an object, trauma to the throat or chest or a severe infection. Burns, hemorrhages and tumors also can cause blockages. Prompt emergency medical attention must be obtained when an obstruction significantly reduces the amount of oxygen that is available to the blood.
![](http://images.wisegeek.com/slideshow-mobile-small/woman-hiker-in-high-altitude.jpg)
Congenital heart issues as well as diseases of the cardiovascular system that occur during the course of life can cause hypoxemia. Often, this ailment is produced when there is a problem in the shunting of the blood between the right atrium and left atrium. Another heart condition that can produce low arterial blood pressure is a damaged or improperly constructed heart valve.
![](http://images.wisegeek.com/slideshow-mobile-small/man-in-striped-shirt-choking.jpg)
One of the most common causes of hypoxemia is lung disease. Cystic fibrosis, which results in thick mucus developing in the lungs, is a serious disease that causes oxygen desaturation. Other lung issues such as emphysema, asthma, chronic obstructive pulmonary disease (COPD) and lung cancer can also produce hypoxemia because of the difficulty in breathing that is present in these disorders.
![](http://images.wisegeek.com/slideshow-mobile-small/young-woman-holding-handful-of-pills.jpg)
Sleep apnea also interferes with the oxygenation of blood. An individual who has sleep apnea does not breathe consistently throughout the sleep process. Instead, pauses in breathing take place. These breathing lapses can last from few seconds to more than a minute in duration and can occur repeatedly during sleep. Hypoxemia results from the lack of oxygen received by the body during these pauses.
![](http://images.wisegeek.com/slideshow-mobile-small/balding-man-coughing-against-white-background.jpg)
The causes of hypoxemia also include the use of anesthetics or narcotics. Post-operative hypoxemia often occurs because of the use of anesthesia, which depresses breathing, during medical procedures. Narcotics, which are commonly used to treat pain, also can decrease the rate of breath to the point at which hypoxemia occurs. People who are being treated with anesthetics or narcotics often require close monitoring of their respiration to quickly identify low oxygen pressure.