Human beings depend on oxygen for life. All organs require oxygen for metabolism but the brain and heart are particularly sensitive to a lack of oxygen. But, What is normal oxygen level by age?
The shortage of oxygen in the body is called hypoxia. Here you can know what is the normal oxygen saturation by age. A serious shortage of oxygen for a few minutes is fatal.
Oxygen level normal range
The normal level of oxygen saturation is 97 to 100%.
Older adults tend to have lower oxygen saturation levels than younger adults. For example, a person over the age of 70 may have an oxygen saturation level of about 95%, which is an acceptable level.
It is important to note that the level of oxygen saturation varies considerably according to a person’s state of health.
Therefore, it is important to understand both the initial readings and the physiology associated with certain natural conditions to interpret oxygen saturation levels and changes in these levels.
Normal oxygen level for obese person
People who are obese or who suffer from conditions such as lung and cardiovascular disease, emphysema, congenital heart disease, and sleep apnea tend to have lower levels of oxygen saturation.
Normal oxygen level for smokers
Smoking can influence the accuracy of pulse oximetry in which SpO2 is low or falsely high depending on the presence of hypercapnia. With hypercapnia, it is difficult for the pulse oximeter to differentiate oxygen in the blood from carbon monoxide (caused by smoking).
Oxygen saturation levels can drop slightly when a person is speaking.
Anemia and oxygen levels
Oxygen saturation can remain normal (for example, 97% and more) for people with anemia. However, this may not indicate adequate oxygenation because there is less hemoglobin to carry an adequate supply of oxygen for people who have anemia.
Inadequate oxygen supply may be more prominent during activity in people with anemia.
Hypothermia and oxygen consumption
Falsely low oxygen saturation levels may be associated with hypothermia, decreased peripheral perfusion, and cold extremities. In these cases, an earlobe pulse oximeter or arterial blood gases would provide a more accurate oxygen saturation level.
However, arterial blood gases are generally only taken in intensive care or emergency settings.
Normal oxygen saturation by age chart
If a pulse oximeter measured your blood oxygen level (SpO2), a normal reading is usually between 95 and 100 percent.
SP02 Oxygen saturation levels. What is normal oxygen level?
| Sp02 | Range | Analysis |
| Normal | 95% ≤ | Normal |
| Hypoxia | 85% – 94% | Low levels |
| Severe Hypoxia | < 85% | Collapse |
What is normal oxygen level by age?
Oxygen saturation, measured by pulse oximetry (SpO2), is a vital clinical measure. Oxygen saturation measurements are illustrated as percentiles. As the altitude increased, SpO2 decreased, especially at altitudes above 2500m.
The increase in altitude had a significant impact on SpO2 measurements for all age groups.
| Oxygen saturation | Oxygen at sea level | Oxygen at High Altitude |
| age years | Spo2 | Spo2 |
| by age 40 | + 95% | = 95% |
| by age 50 | + 95% | = 95% |
| by age 60 | + 95% | = 95% |
| by age 70 | + 90% | = 90% |
| by age 80 | + 90% | = 90% |
| by age 90 | + 90% | = 90% |
Normal oxygen saturation by age 70
Normal oxygen saturation by age 80
Normal oxygen saturation by age 90
Normal blood oxygen levels
Hypoxemia is a below-normal level of oxygen in the blood, specifically in the arteries. Hypoxemia is a sign of a problem related to breathing or circulation and can lead to various symptoms, such as shortness of breath.
Hypoxemia is determined by measuring the oxygen level in a sample of blood drawn from an artery (arterial blood gas).
It can also be estimated by measuring the oxygen saturation of the blood with a pulse oximeter, a small device that is attached to the finger.
Normal arterial oxygen is about 75 to 100 millimeters of mercury (mm Hg). Values below 60 mm Hg usually indicate the need for supplemental oxygen.
Normal pulse oximeter readings typically range from 95 to 100 percent. Values below 90 percent are considered low.
How to check oxygen level?
The most effective way to monitor blood oxygen levels is with an arterial blood gas or ABG test. For this test, a blood sample is taken from an artery, usually in the wrist. This procedure is very precise, but it can be a bit painful.
An ABG test can be difficult to do at home, so a person may want to do an alternate test, using a small device known as a pulse oximeter.
A pulse oximeter is a small clip that is often attached to a finger, although it can also be worn on the ear or toe. It measures oxygen in the blood indirectly by absorbing light through a person’s pulse.
Although the pulse oximeter test is easier, faster, and painless, it is not as accurate as the ABG test.
This is because it can be influenced by factors such as dirty fingers, bright lights, and poor circulation in the extremities.
For people who want to buy a pulse oximeter, there is a range of easy-to-use devices available online.
FDA approved Oximeter made in the USA
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SpO2 normal range by age Chart
This reading chart provides guidance on what oxygen level means and when and how to seek medical help.
Average Oxygen Level
What are average readings? A normal oxygen level is usually 95% or more.
Blood Oxygen Level Test
Oximetry is a test used to measure the level of oxygen (oxygen saturation) in the blood.