Hypoxemia refers to a low oxygen level in your blood, particularly in arterial blood. Blood is the medium that carries oxygen and nutrition to the rest of your body. If your blood has a low oxygen level, it can affect the functioning of multiple organs. Blood oxygen saturation level can be checked at home using a pulse oximeter. If your oxygen saturation level falls below 90%, it is considered an indication of hypoxemia. Severe hypoxemia can lead to life-threatening complications and should be treated as a medical emergency.
There are multiple causes of hypoxemia. It can be caused by environmental factors, individual health factors, and underlying medical conditions. Traveling to or living at high altitudes can lead to hypoxemia because these regions have a low oxygen supply. Chronic respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), or emphysema can also cause hypoxemia. Due to these respiratory diseases, the supply of oxygen from your lungs to your blood declines. Other respiratory diseases that can cause hypoxemia include acute respiratory distress syndrome (ARDS), pneumonia, pneumothorax, pulmonary edema, pulmonary embolism, sleep apnea, pulmonary fibrosis, and interstitial lung disease.
Cardiovascular diseases can also lower the oxygen saturation of the blood. These diseases include anemia, congenital heart defects in children, and congenital heart diseases in adults. Certain medications such as narcotics and anesthetics are also capable of causing hypoxemia because they can lower your respiratory rate.
The risk factors of hypoxemia are linked with its causes. You are at risk if you frequently travel at a high altitude or live in high altitude areas such as a hill station. Genetic disease of the heart or lungs can increase the risk of hypoxemia from a young age. People with chronic respiratory diseases such as asthma, COPD, and emphysema are also at higher risk because their lungs are unable to deliver the required amount of oxygen. Long-term use of medications that lower your breathing rate can also put you at risk.
The prevalence of hypoxemia is variable because it depends on the incidence of its causative factors. Hypoxemia can occur at any age, but the risk may increase with age, especially in people with pre-existing cardiovascular or respiratory issues.
Mild hypoxemia can present with headaches and tiredness. In case of moderate to severe hypoxemia, you may experience multiple symptoms such as difficulty in breathing, shortness of breath, attempts at fast or deep breathing, rapid heartbeat, coughing, wheezing, bluish discoloration of lips or fingernails, confusion, and disorientation. Shortness of breath can develop even in a state of rest, and it may worsen upon performing physical activity. Based on your underlying medical condition, you may also develop other symptoms such as sleep disturbance, feeling of choking, generalized fatigue, etc.
The diagnosis of hypoxemia begins with identifying its underlying cause. For this purpose, a detailed medical history is taken, followed by a physical examination. Your doctor can assess the signs of hypoxemia, such as rapid pulse, fast respiratory rate, bluish skin discoloration, etc., in a physical exam. The oxygen level in the blood can be determined by pulse oximetry or arterial blood gas test (ABGs). Pulse oximetry is done using a small device that gets attached to your finger. It measures the percentage of oxygen in your blood. In case of ABGs, a needle is inserted in your artery to draw a blood sample, which is used to determine blood oxygen levels. Pulmonary function tests can be done to evaluate your breathing. Imaging techniques such as chest x-rays, CT scans, or MRI can be done to give an accurate visualization of the root cause.
Hypoxemia itself is a manifestation of many respiratory and cardiovascular diseases. The exact cause needs to be determined and differentiated from other similar conditions before proceeding with treatment. Differentiation between the causes of shortness of breath and other symptoms can be made on the basis of history, physical examination, and diagnostic tests.
Treatment of hypoxemia is focused on increasing the oxygen levels in your blood. This can be done by using oxygen therapy via a face mask. Oxygen is delivered by a device through a tube that connects to your facemask. These devices can be present at a hospital or available in portable forms as well. The amount of oxygen delivered is decided by your doctor based on your individual requirement. In most circumstances, you will be monitored closely until your oxygen saturation level rises above 97 percent, as indicated by a pulse oximeter.
Medications can be given to treat the underlying cause. For example, if a patient has asthma, they can be given inhalational corticosteroids or bronchodilators to improve breathing.
The overall prognosis of hypoxemia is good if it gets diagnosed and treated earlier. Treatment with oxygen therapy can reverse the adverse effects of hypoxemia. In the absence of immediate medical treatment, hypoxemia can damage your vital organs and be fatal.
Hypoxemia can be prevented to a certain degree by improving your lifestyle factors. If you have a known respiratory or cardiovascular disease, consult your doctor for regular health checkups to notice any decline in the oxygen level at an early stage. You can also carry a portable pulse oximeter to monitor your health. Avoid smoking as it damages your lung tissues and restricts blood flow. Also, try to avoid air pollution as much as possible to reduce the risk of tissue irritation. Contagious respiratory infections can be prevented by using a mask and washing your hands frequently.
Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 22, 2023.
Hypoxemia - an overview | ScienceDirect Topics
Low blood oxygen (hypoxemia) - Mayo Clinic