What are the normal blood oxygen values


Do you know what are the values considered normal for oxygen in the blood? The saturation of oxygen in the blood is a measure with which the amount that our bloodstream has of O2 is obtained. That is, when the heart pumps blood to the rest of our body, this flow is first transported to the lungs, where a certain amount of oxygen molecules bind to red blood cells or erythrocytes.

What are the normal blood oxygen values

This percentage of globules that are saturated with oxygen is what is measured with a device known as a finger oximeter, although it can also be calculated with a more accurate test known as a blood gas. With this type of test, we will be able to know if our blood oxygen levels are within the healthy or not. In the following article we tell you what the normal blood oxygen values are. Read on and find out!

What are the normal values of oxygen in the blood – here the answer

As we have indicated, blood oxygen saturation is a parameter that measures the number of red blood cells (also known as erythrocytes) that have been saturated with O2. This measurement is carried out to check the respiratory function of a person and is performed with the help of a pulse oximeter or finger oximeter, which is fastened either on the finger or in the earlobe of a certain patient and analyzes the changes that occur in the color of the blood due to the pressure of the device.

There is also another much more accurate test known as arterial blood gas where the amount of both oxygen and carbon dioxide in the blood is measured, according to MedlinePlus [1]. This test includes parameters such as the content and saturation of oxygen and hemoglobin in the blood, the pH of the blood flow and the partial pressure of both O2 and carbon dioxide in the blood.

Once these tests have been performed, it is normal for the patient to wonder what the normal blood oxygen values are. According to data from the Mayo Clinic [2], the normal oxygen level ranges between 75- and 100-mm Hg (millimeters of mercury), with those below 60 mm Hg being considered as low values. In this way, as we can see, the minimum level of oxygen in the blood would be 75 mm Hg. In the case of using a pulse oximeter, the Mayo Clinic considers that healthy values are between 95 and 100% and those below 90% are rated as low.

What happens when the blood oxygen level is low

In the event that you have measured your blood oxygen saturation either with a pulse oximeter or with arterial blood gas and the results are considered to be below normal, it is normal to ask yourself: “What happens when blood oxygen levels are low?” When the patient has oxygen levels below 60 mm Hg or with less than 90% saturation, that is, he has a lack of oxygen in the blood, he is considered to have hypoxemia.

Hypoxemia, also known as oxygen desaturation, is a condition where the patient has deficient oxygen levels in the arteries, that is, it occurs when the saturation of O2 in the blood is below normal, approximately 90%. When the saturation value becomes below 80%, specialists call it severe hypoxemia, where the most common symptom is respiratory distress.

You may also be interested in what are the normal values of hemoglobin in blood.

Causes and symptoms of hypoxemia

Hypoxemia is a problem that usually appears as a symptom of other respiratory problems. According to the Mayo Clinic [3], among the main causes that cause this condition, we find the following:

  • Anemia
  • Asthma
  • Congenital heart disease in adults
  • Pulmonary emphysema
  • Chronic obstructive pulmonary disease (COPD)
  • Pneumonia
  • Pulmonary edema
  • Pulmonary embolism
  • Acute respiratory distress syndrome
  • Sleep apnea
  • Use of some medications such as anesthetics and narcotics

Although it also depends on what type of cause is causing hypoxemia, among its most general symptoms are:

  • Shortness of breath
  • Headache
  • Frequent periods of nausea and/or vomiting
  • Lack of concentration and coordination problems
  • Numbness
  • Bluish skin

If you have several of the following symptoms or have experienced problems such as having a respiratory illness, a head injury or smoke inhalation or carbon monoxide poisoning, it is important that you go to the health care staff as soon as possible for an arterial blood gas.


Leave a Reply