What is hypoxemia?

Hypoxemia is a medical condition in which low blood oxygen levels occur throughout the body. Oxygen levels are often measured in percent, and anything between 95 and 100% is usually considered normal. Some conditions can cause oxygen levels to drop far below this, and if a person has 90% oxygen saturation or less, they may be diagnosed with hypoxemia. Some people may have much lower saturation levels, making the condition more serious. In certain cases, people with conditions such as congenital heart defects may have chronically low saturation levels in the 80s or lower, particularly if they have heart bypasses.

There are many potential causes of hypoxemia. Many of these have to do with lung function. Inhaling certain substances such as carbon monoxide in large amounts can lower the level of oxygen in the blood. Simple conditions, such as pneumonia, can sometimes make it difficult for blood to be properly oxygenated when it reaches the lungs. Other lung conditions that can cause hypoxemia include emphysema, chronic obstructive pulmonary disease, or pulmonary embolism. Almost any condition that reduces lung function, whether temporary, such as reaching a very high altitude suddenly, or more permanently, can affect the lungs' ability to oxygenate the blood.

As mentioned, certain heart conditions can also lead to hypoxemia. Whenever blood flow is less than normal, not enough blood can flow to the lungs to be oxygenated. Another possible cause is anemia, where there are too few red blood cells to carry oxygen to the body's tissues.

The main symptom of hypoxemia may be shortness of breath, but other potential symptoms include paleness, weakness, fatigue, and bluish skin in the extremities, particularly around the fingernails and toenails. Long-term oxygen deficiency can lead to other problems, such as popping fingers and toes.

How to treat this condition largely depends on its causative factors. Bacterial pneumonia would probably be treated with antibiotics, and whether these were oral or intravenous would depend on the severity of the infection and the level of hypoxemia. For chronic conditions, oxygen could be used to raise oxygen saturation levels in the blood. Essentially, doctors would attend to the underlying condition, but could also provide supportive treatment such as oxygen or respiratory support, while giving treatment time to work.

The causes and treatment of hypoxemia are varied, but people should consider the symptoms of this condition, particularly shortness of breath, as a serious sign. If shortness of breath occurs without a plausible explanation, such as strenuous exercise, or if it occurs suddenly, immediate medical help is usually needed.

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