You need to know the normal oxygen level in the blood, which must be maintained. This is because, without sufficient oxygen levels, the body's ability and tissues to carry out their functions will be disrupted.
In some diseases, the value of oxygen levels in the blood or oxygen saturation can be used to monitor the body's condition. This value is also used to determine whether a treatment is successful or needs to be re-evaluated.
Normal Oxygen Levels in Blood
The amount of normal oxygen content can be found in different forms, depending on the measurement method. There are 2 ways to measure oxygen saturation in the blood, namely with a blood gas analysis or a pulse oximeter. Here is the explanation:
Blood gas analysis
Blood gas analysis is a blood test that is taken through an artery. Apart from measuring oxygen saturation (SaO2) or oxygen levels in the blood, this test also measures the partial pressure of oxygen (PaO2), the partial pressure of carbon dioxide (PaCO2), levels of bicarbonate (HCO3), and pH of arterial blood.
This blood gas analysis test is very accurate. The measurements are also carried out in the hospital and must be done by professional medical personnel. The results of normal and abnormal oxygen levels on blood gas analysis tests are as follows:
High oxygen level
Oxygen partial pressure (PaO2): above 120 mm Hg
Normal oxygen levels
Oxygen saturation (SaO2): 95–100%
Oxygen partial pressure (PaO2): 80–100 mm Hg
Low oxygen level
Oxygen saturation (SaO2): below 95%
Oxygen partial pressure (PaO2): below 80 mm Hg
A pulse oximeter is an oxygen saturation check tool that is quite practical and can be used alone at home. This tool estimates the amount of oxygen in the blood by sending infrared light to the capillaries. The oxygen level in the blood is measured by the amount of light reflected from the capillaries.
Compared to AGD, it has a measurement error tolerance of 2%. This means that the test results of oxygen levels in the blood can be 2% higher or lower than the actual level.
Even so, the pulse oximeter is still very useful for seeing blood oxygen levels. This tool is also often used in hospitals to quickly assess the patient's heart and respiratory function.
The result of the pulse oximeter measurement shows the percentage of oxygen saturation (SpO2). The results of normal and abnormal blood oxygen levels on the pulse oximeter are as follows:
Normal oxygen saturation: 95–100%
Low oxygen saturation: below 95%
Interpretation of Oxygen Levels in Blood
People who are healthy and have no complaints will generally have normal blood oxygen levels. In other cases, a person can look healthy and have no symptoms but have low blood oxygen levels. This condition is called happy hypoxia and can be found in sufferers of COVID-19.
Low oxygen levels or hypoxemia generally cause various symptoms, such as shortness of breath, chest pain, cold sweats, coughing, confusion, and blue skin. Apart from COVID-19, hypoxemia can be caused by:
- Chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema
- Acute respiratory distress syndrome (ARDS)
- Congenital heart defects
- Heart disease
- Pulmonary embolism
Most of the aforementioned diseases or medical conditions can block the lungs from obtaining oxygen and releasing carbon dioxide optimally. Some of them are blood disorders and problems with the circulatory system, which can also reduce oxygen distribution throughout the body.
Conditions of blood oxygen levels that are too high are rarely found but can happen. Usually, this is experienced by people who are receiving oxygenation therapy using additional oxygen cylinders. This condition can only be detected by the AGD test.
To find out the oxygen level in the blood, you can do a blood gas analysis test at the hospital. However, this test cannot be done haphazardly but must go through a doctor's recommendation. If you want to be more practical, you can buy a pulse oximeter to check the blood's oxygen level at home.
If you experience hypoxemia symptoms, such as shortness of breath, cold sweat, and weakness, or find low blood oxygen levels on the pulse oximeter, immediately go to the emergency room or the nearest doctor for further tests and appropriate treatment.