What is the normal amount of oxygen in the blood? Symptoms of deficiency and ways to treat it
Blood oxygen level is a measure of how much red blood cells carry oxygen. Oxygen enters the body through the nose and mouth and enters the bloodstream through the lungs.
Oxygen in the bloodstream is effective in replacing worn-out cells, providing the body with the energy it needs, helping the immune system function, and more.
Low blood oxygen levels indicate a problem with the lungs or circulatory system.
In this article, we describe the normal level of oxygen in the blood and the symptoms of hypoxia in the body and explain the methods of measuring blood oxygen levels and ways to increase oxygen uptake.
Why is blood oxygenation important?
About 90% of our energy comes from breathing. Cells need oxygen to break down the chemical bonds of food molecules (such as sugars, carbohydrates, and proteins) and release the energy in them. Delivering oxygen to cells and muscles enables us to perform physical activities.
Oxygen is the most important substance for cells. All bodily functions depend on oxygen. Lack of oxygen in the blood causes us to be unable to exercise and feel tired . In respiration, oxygen reaches the cells through the lungs, causing the brain to work and the heart to beat; Therefore, breathing is undoubtedly the most important priority for the body. By performing tail breathing muscle (IMT) exercises using the Airofit device, we can significantly increase the amount of oxygen in our blood.
What is the normal amount of oxygen in the blood?
The amount of oxygen in the blood is called the level of oxygen saturation in the blood. In medical terms, the amount of oxygen in the blood is indicated in the ABG test with PaO2 and in the pulse oximeter with O2 sat (SpO2) . Using the following tips, you can better understand the meaning of your test results:
Normal rate
Normal blood oxygen levels in the ABG test for healthy lungs are between 80 and 100 mm Hg (mm Hg). If you measure your blood oxygen level with a pulse oximeter (SpO2), your normal blood oxygen level is usually between 95% and 100%. Of course, these limits do not apply to COPD or other lung diseases, and your doctor will determine what is normal for your particular condition and disease; For example, in people with severe COPD, blood oxygen level (SpO2) between 88% and 92% is not uncommon.
Less than normal
Blood oxygen levels below normal are called hypoxemia. Hypoxemia is usually a concern. The lower the oxygen level, the more severe the hypoxemia. Hypoxemia can lead to complications and problems in tissues and organs.
Normally, PaO2 below 80 mm Hg or SPO2 below 95% is considered low. SPO2 is less than 90% critical and may cause damage to the heart, lungs and liver. It is important to know the normal level of oxygen in the blood; Especially if you have chronic lung disease. Your doctor will advise you on acceptable oxygen levels.
More than normal
If you do not use breathing apparatus for breathing, your blood oxygen level is unlikely to rise too high. In most cases, high oxygen levels are seen only in people who take supplemental oxygen. High blood oxygen levels can be detected on an ABG test.
What happens if the blood oxygen level is too low?
You may experience the following symptoms when your blood oxygen level is out of the normal range:
- Headache ;
- Breathlessness ;
- Chest pain ;
- Rapid heartbeat ;
- Confusion.
If low blood oxygen levels continue, you may experience signs of bruising or cyanosis. A clear sign of this disease is a change in skin color to blue in the nail bed and mucous membranes.
What causes low blood oxygen levels?
Diseases and problems that negatively affect blood oxygen levels include:
- Asthma ;
- Anemia ;
- Pulmonary embolism ;
- Heart disease ;
- Congenital heart defect;
- Acute Respiratory Distress Syndrome (ARDS);
- Collapsed Lung;
- COPD, including chronic bronchitis and emphysema .
These diseases and problems may prevent enough oxygen from being inhaled and carbon dioxide released into the lungs. Blood disorders and circulatory system problems may also prevent oxygen from being absorbed into the bloodstream and transmitted throughout the body. Any of these problems or disorders may reduce the level of oxygen saturation in the blood. Symptoms of hypoxemia appear as blood oxygen levels drop.
In smokers, the figure displayed on the pulse oximeter may be high, because smoking causes carbon monoxide to accumulate in the blood, and the pulse oximeter cannot tell the difference between carbon monoxide and oxygen. If you are a smoker and need to know your blood oxygen level, an ABG test is the only way to accurately diagnose your blood oxygen level.
Methods of measuring blood oxygen levels
Most children and adults do not need to control their blood oxygen levels. In fact, many doctors do not measure blood oxygen levels until they see signs of problems such as shortness of breath or chest pain. However, controlling blood oxygen levels in people with chronic conditions such as asthma, heart disease, and chronic obstructive pulmonary disease (COPD) is essential because it shows whether or not treatments are effective.
Blood oxygen levels are measured in the following two ways:
1. Arterial blood gas test or ABG
An arterial blood gas ( ABG) test is a test in which the amount of oxygen in the blood is measured; Of course, this test also measures the amount of other gases in the blood, as well as the pH (level of acidity or alkalinity of the blood). The ABG test is very accurate but aggressive. For this test, blood is drawn from an artery, not a vein or vein. The arteries, unlike the veins, have a pulse and the blood drawn from the arteries has oxygen; While the blood in the veins does not have oxygen.
In this test, blood is taken from the artery of the wrist; Because it feels more comfortable than other arteries in the body. The wrist is a sensitive area and drawing blood from this area is difficult and unpleasant. The arteries are deeper than the veins, which makes the test more uncomfortable.
2. Using Pulse Oximeter
A blood pulse oximeter is a non-invasive device that measures the amount of oxygen in the blood. This is done by sending infrared light to the capillaries of the fingers or toes or the soft tissues of the ear. The amount of light reflected from the gases is then measured. Light rays measure blood oxygen levels as well as heart rate. Small beams of light analyze the color and movement of blood cells. Dark red blood cells indicate a lack of oxygen, and light red blood cells indicate a good amount of oxygen in the blood.
The oxygen meter, called the SPO2 level, shows what percentage of the blood is saturated. SPO2 stands for “Peripheral Capillary Oxygen Saturation”; That is, oxygen saturation in the blood is measured. SPO2 is an estimate of the amount of oxygen that the blood carries at its maximum capacity. If 95% of your blood cells are bright red and 5% are dark red, your SPO2 will be 95%. The error rate of this test is 2%; This means that the figure shown may be 2% higher or lower than the actual blood oxygen level.
Measuring blood oxygen with an oximeter at home
Because the blood oxygen meter is a non-invasive tool, you can also use it at home. This device is available in many medical stores or online stores. Before using this device, talk to your doctor to learn how to use and interpret the results and figures on it; For example, if your hand is not stationary while using the device, the result will be wrong and the device will show different numbers. Also, things like dark nail polish or cold hands and feet can cause the displayed number to be lower than normal (your doctor may remove your nail polish before using the device or if the figure on it is abnormally low). .
How do we get more oxygen?

If your blood oxygen level is very low, you should increase your blood oxygen saturation. This is usually done using supplemental oxygen. Home oxygen supplementation is a type of treatment that requires a doctor’s prescription. You should follow your doctor’s advice on how to use home oxygen to avoid complications.
There are other ways to get more oxygen. Cardio training is one of these methods. Of course, just focusing on exercise is not enough when you want to increase your blood oxygen level. With cardio, we train the cardiovascular and respiratory systems, but that does not mean that breathing is optimized.
You can use the following 5 methods to get more oxygen:
1. Inhalation of fresh air
Open the windows and leave the house. Fresh air gives you energy and pushes more oxygen into your lungs.
2. drinking water
The lungs must be hydrated to supply oxygen and excrete carbon dioxide. Drinking enough water affects the oxygen level of the blood. On average, we lose about 400 milliliters of water a day.
3. Consume foods rich in iron
Some foods increase the level of oxygen in the blood. Iron is a mineral needed by red blood cells. Red blood cells are cells that carry oxygen throughout the body. For this reason, when we are iron deficient, we feel tired. Sources of iron include green leafy vegetables such as kale and kale, fruits such as apples, legumes and lean proteins such as eggs, chicken and fish.
4. Exercise
The more oxygen we receive and consume, the more energy the body’s cells produce, so increasing oxygen consumption increases our endurance. There is a clear relationship between performance and the amount of oxygen we receive, which is measured by the maximum oxygen consumption or VO2 max. The higher the VO2, the greater the endurance. Interval and sprinting exercises are the best exercises to increase oxygen levels.
5. Perform breathing exercises
If you want to improve the quality of your breathing, exercise alone is not enough; Because exercise does not necessarily lead to full lung capacity and oxygen uptake.
Slow, deep breathing increases blood oxygen levels. Oxygen is carried to the bloodstream through the respiratory system and therefore, if our respiration is not optimal, it affects the oxygen level of the blood. For this reason, when many people and athletes use breathing exercises, they see a big difference. Breathing exercises increase endurance and are also effective in reducing stress levels through concentration and calmer breathing.
Relationship between blood oxygen levels and sleep
Sleep is a good time to repair and rebuild the body. In sleep, many changes and transformations take place that we are unaware of. Many of these changes, such as cell renewal and tissue repair and memory consolidation , are associated with oxygen saturation levels in the body. Stable oxygen supply is essential for these processes. Sometimes sleep quality is compromised by low oxygen levels. Fortunately, there are many tools and techniques to increase blood oxygen levels and maximize repair and regeneration during sleep.
The role of oxygen in every stage of sleep
When we slowly enter the early stages of sleep from waking up, the breathing rate becomes a little slower and more regular, and there is a slight drop in body temperature. As we move into the deeper stages of sleep, our heart rate slows down as the body relaxes and patterns of brain activity change. Growth hormone is produced and increases tissue growth and repair. When we enter REM (rapid eye movement) sleep, more oxygen reaches the muscles, brain activity increases again, the eyes move rapidly under the eyelids, and vivid sleep usually occurs at this stage. Finally, we wake up REM and wake up.
The effect of oxygen deprivation on sleep quality
Constant and uninterrupted breathing during sleep causes us to be full of energy when we wake up; But many people are deprived of sleep, which means that the amount or quality of sleep at night is not enough. It is estimated that up to one billion people worldwide have sleep apnea . Sleep apnea is a condition in which breathing stops periodically during sleep. Shortness of breath means lack of oxygen, and this is exactly what happens in sleep apnea.
Increased blood oxygen levels during sleep

There are many ways to naturally increase oxygen saturation, many of which are very cheap or free. Usually, developing good habits during the day that lead to adequate oxygen uptake can increase oxygen levels during sleep. You can use the following methods to increase blood oxygen levels during sleep:
1. Practice deep breathing
Deep breathing exercises have a calming effect, but the benefits go beyond having a calmer mind and increase blood oxygen levels. You can increase the effect of deep breathing by getting out into the fresh air and away from car pollution.
2. To lie down
Most people breathe better when they sleep on their side. The reason is also very simple: gravity. When we sleep on our backs, the weight of the body puts pressure on the airways and lungs, causing unnecessary obstructions. We have long known that sleeping on your side protects the airways from unwanted obstructions and reduces snoring.
3. Reduce and manage stress
There are many strategies for managing stress : exercise, meditation , coaching , yoga and even mindfulness apps. We live in a world full of stress, but fortunately there are many ways to help overcome it.
4. Exercise
During exercise, when the rate of respiration increases, the level of oxygen in the blood also rises naturally. When we exercise, our cells use up more oxygen than we do in our daily activities. When the brain detects an increase in the production of carbon dioxide in the body, it increases the rate of respiration to excrete carbon dioxide and deliver more oxygen to the body.
5. Avoid alcohol before bedtime
Sometimes alcohol and other sedatives cause the throat to relax too much and increase the risk of sleep apnea. Muscle relaxation increases the likelihood of airway collapse. Avoiding alcohol in the 4 hours before bedtime dramatically improves breathing and oxygen levels during the night. Alcohol consumption usually causes interrupted sleep; That is, it prevents the deep and restorative sleep that the body needs for its complete renewal and renewal.
Concluding remarks
Here we are familiar with the methods of measuring blood oxygen levels, the causes and symptoms of hypoglycemia and ways to treat hypoxia in the body. You may be thinking of buying a pulse oximeter while reading this article; But if you do not have any of the underlying diseases mentioned above, you do not need to buy this device.