Blood Oxygen Level: What It Is & How To Increase It (2024)


What does blood oxygen level mean?

Your blood oxygen level (blood oxygen saturation) is the amount of oxygen you have circulating in your blood.

Oxygen is essential to life, and our bodies need a certain amount of oxygen to function properly. Oxygen enters your body through your nose or mouth when you breathe (inhale) and passes through your lungs into your bloodstream. Once in your bloodstream, the oxygen then goes to cells all over your body. All of your cells need oxygen to create energy efficiently, and your body needs energy to fulfill all of its processes, such as digestion and even thinking.

Once your cells use oxygen, they create carbon dioxide. Your bloodstream then carries the carbon dioxide back to your lungs, and you breathe it out (exhale it) through your mouth or nose.

Your body tightly regulates the amount of oxygen saturation in your blood, because low blood oxygen levels (hypoxemia) can lead to many serious conditions and damage to individual organ systems, especially your brain and heart. Low blood oxygen levels indicate that your lungs and/or circulatory system may not be working as they should.

What is a blood oxygen level test?

There are two main ways to measure or test blood oxygen levels: through a blood draw test and through pulse oximetry (using an oximeter). A blood draw test provides much more information about your oxygen levels than an oximeter does.

Oxygen level blood draw test

Healthcare providers can measure your blood oxygen level as part of a larger test known as an arterial blood gas (ABG) test. An ABG test measures the level of oxygen and carbon dioxide in your blood. The test also checks the balance of acids and bases, known as the pH balance, in your blood. Having too much or too little acid in your blood can be harmful to your health.

Pulse oximetry

A pulse oximeter can also measure blood oxygen saturation levels through a small clip that’s usually placed on your finger or toe. An oximeter reading only indicates what percentage of your blood is saturated with oxygen, known as the SpO2 level, as well as your heart rate. It’s a quick and harmless way to check if someone’s blood oxygen level is too low.

Healthcare providers use pulse oximeters frequently in hospitals. You can also use a pulse oximeter at home — you can usually buy one from a pharmacy or certain stores and websites.

Why do I need to have my blood oxygen level tested?

Your healthcare provider may have you undergo a blood oxygen level test if you’re experiencing any of the following acute (sudden and serious) conditions:

  • If you’re having trouble breathing. (A newborn baby may also need a blood oxygen test if they are having trouble breathing).
  • If you’ve recently injured your head or neck, which can affect your breathing.
  • If you have coronavirus disease (COVID-19).
  • If you have pneumonia.
  • If you have carbon monoxide poisoning.
  • If you have a smoke inhalation injury.
  • If you’ve had multiple episodes of nausea and/or vomiting.
  • If you’ve had a drug overdose.

Your provider may also perform a blood oxygen test if you have any of the following lung conditions to make sure your treatment is working properly:

  • Asthma.
  • Chronic obstructive pulmonary disease (COPD).
  • Cystic fibrosis.
  • Heart disease.

If you’re receiving oxygen therapy while in a hospital, your provider will likely monitor your blood oxygen level to make sure you are getting the right amount of oxygen.

How can I increase my blood oxygen level?

There are some ways to naturally increase the amount of oxygen in your blood, including:

  • Breathing in fresh air: Opening your windows or going outside for a walk can increase the amount of oxygen that your body brings in, which increases your overall blood oxygen level.
  • Quitting smoking: Only two to three weeks after you quit smoking, your circulation will likely improve significantly. After one to nine months, your shortness of breath decreases. Both of these aspects contribute to your body’s ability to take in more oxygen.
  • Practicing breathing exercises: Simple breathing exercises like pursed-lip breathing and deep belly breathing can open your airways and increase the amount of oxygen in your blood.

You can use a pulse oximeter at home to check your blood oxygen level and see if these natural ways to increase your oxygen intake work for you.

However, it’s important to note that if you have an underlying condition, especially a severe illness such as pneumonia or carbon monoxide poisoning, these natural remedies may not be enough to increase your blood oxygen to an acceptable level.

If you experience signs of hypoxemia, get to the nearest hospital as soon as possible.

Test Details

Who performs a blood oxygen level test?

A healthcare provider specialist called a respiratory therapist usually performs blood draws for blood oxygen level tests that are a part of arterial blood gas tests from an artery in your wrist. The sample is then either processed by the respiratory therapist or sent to a lab very quickly where medical laboratory scientists process the sample.

Any healthcare provider can apply a pulse oximeter to check your blood oxygen saturation level. You can also use a pulse oximeter on yourself or someone else at home.

What happens before a blood oxygen level test?

If a respiratory therapist is taking a blood sample from an artery in your wrist, they may perform a blood circulation test called an Allen test before taking the sample. An Allen test involves holding your hand high with a clenched fist. Your provider will then apply pressure to the arteries in your wrist for several seconds. This simple test makes sure both of the arteries in your wrist are open and working properly.

If you’re on supplemental oxygen therapy, your provider may turn off your oxygen for about 20 minutes before the blood draw. This is called a room air test. If you’re unable to breathe without supplemental oxygen, your provider will not do this test.

What should I expect during a blood oxygen level test?

Most blood tests take a blood sample from one of your veins. For a blood oxygen level test that’s part of an arterial blood gas test, a respiratory therapist will take a sample of blood from one of your arteries. This is because there are higher oxygen levels in blood from an artery than blood from a vein.

A respiratory therapist usually takes the sample from an artery inside your wrist known as the radial artery. Sometimes they may take a sample from an artery in your elbow or groin. If a newborn is undergoing a blood oxygen level test, they may take the sample from the baby's heel or umbilical cord.

Unfortunately, getting a blood sample from an artery is usually more painful than getting a sample from a vein. This is because arteries are deeper than veins and are surrounded by nerves. You may feel light-headed, dizzy or nauseated while a respiratory therapist takes blood from your artery.

A blood oxygen level test blood draw includes the following steps:

  • You’ll sit in a chair or lie in a medical bed, and a respiratory therapist will look for an artery — usually in your inner wrist. They might use ultrasound imaging to help find an artery.
  • Once they’ve located an artery, they’ll clean and disinfect the area.
  • They’ll then insert a small needle into your artery to take a blood sample. You may feel a sharp pain as the needle goes into your artery.
  • After they insert the needle, a small amount of blood will collect in a syringe.
  • Once they have enough blood to test, they’ll remove the needle and hold a cotton ball or gauze on the site to stop the bleeding. They may apply pressure for 5 to 10 minutes or longer if you’re taking blood-thinning medication.
  • They’ll place a bandage over the site, and you’ll be finished.

A blood oxygen saturation test with the use of a pulse oximeter includes the following steps:

  • Your healthcare provider will clip a small, plastic electronic device called a pulse oximeter on a part of your body — usually your fingertip.
  • The oximeter will send a special type of light called infrared light that will pass through your skin and into the blood in your capillaries. This is harmless and you won’t feel anything.
  • The oximeter then measures how much light is reflected off the hemoglobin molecules in your blood. This is used to determine your blood oxygen level.
  • After a few seconds, the oximeter will provide a number that corresponds to your heart rate and oxygen level.

You can also use a pulse oximeter at home. It’s important to keep in mind the factors that can reduce the accuracy of pulse oximeter readings, which include:

  • Having nail polish on the finger or toe you’re testing.
  • High-intensity lighting in the room you’re using the oximeter.
  • Excessive movement while using the oximeter.

What should I expect after my blood oxygen level test?

If you’ve had a blood draw, you may experience some bruising and/or soreness at the site of the needle injection. Your provider may recommend that you avoid lifting heavy objects for 24 hours after the blood draw.

Results and Follow-Up

What do the results of a blood oxygen level test mean?

Blood test reports, including blood oxygen level test reports, usually provide the following information:

  • The name of the blood test or what was measured in your blood.
  • The number or measurement of your blood test result.
  • The normal measurement range for that test.
  • Information that indicates if your result is normal or abnormal or high or low.

If your blood oxygen level blood test results are not normal, it may mean you:

  • Aren’t taking in enough oxygen.
  • Aren’t getting rid of enough carbon dioxide.
  • Have an imbalance in your blood pH (it’s too acidic or basic).

A blood oxygen level test can't diagnose specific conditions. If your results are not normal, your healthcare provider will have you undergo more tests to confirm or rule out a diagnosis.

What is a normal blood oxygen level?

Laboratories may have different reference ranges for the aspects of your blood that are measured in a blood oxygen level test. When you get your blood test results back, there will be information that indicates what that lab’s normal ranges are for each measurement. If you have any questions about your results, be sure to ask your healthcare provider.

For most people, a normal pulse oximeter reading for your oxygen saturation level is between 95% and 100%. If you have a lung disease such as COPD or pneumonia, your normal oxygen saturation level may be lower. Your healthcare provider will let you know what levels are acceptable. Your oxygen saturation levels may also be lower if you live in an area with high elevation.

It’s important to note that pulse oximeters are not always accurate. Your actual blood saturation level may be 2% to 4% higher or lower than what the oximeter reads. For a more accurate result, your provider may check your blood oxygen levels with a blood test.

What does a low blood oxygen level mean?

A lower-than-normal blood oxygen level is called hypoxemia. Since oxygen is essential to all of your body’s functions, hypoxemia is often concerning. The lower the oxygen level, the greater likelihood for complications in body tissue and organs.

A variety of conditions and circ*mstances can interfere with your body’s ability to deliver normal levels of oxygen to your blood. Some of the most common causes of low blood oxygen levels (hypoxemia) include:

  • Heart conditions.
  • Lung conditions such as asthma, emphysema, and bronchitis.
  • Strong pain medications or other problems that slow breathing.
  • Sleep apnea (impaired breathing during sleep).
  • Inflammation or scarring of your lung tissue.
  • Locations of high altitudes, where oxygen in the air is lower.

If you have a low blood oxygen level, your healthcare provider will likely have you undergo further testing to determine what is causing your low oxygen levels. A blood oxygen level test alone cannot determine the cause.

When should I know the results of my blood oxygen level test?

The results for a blood sample oxygen level test are usually available right away (within minutes).

A pulse oximeter reveals your oxygen saturation level within seconds.

When should I call my doctor?

If you’re using an oximeter at home and your oxygen saturation level is 92% or lower, call your healthcare provider. If it’s at 88% or lower, get to the nearest emergency room as soon as possible.

If you have a chronic lung condition, such as COPD or asthma, you’ll likely need to see your healthcare provider regularly to make sure your treatment is working. If you develop concerning symptoms related to your lung condition, call your provider as soon as possible.

Frequently Asked Questions

Is having a low blood oxygen level a sign of COVID-19?

COVID-19 affects people in different ways. Infected people have had a wide range of symptoms — from mild symptoms to severe illness. Some — but not all — people infected with COVID-19 experience low blood oxygen levels. Just because you have a normal blood oxygen level doesn’t mean you don’t have COVID-19 if you’re experiencing other symptoms. Similarly, you could have a low blood oxygen level and not have COVID-19.

The only way to know for sure if you have COVID-19 is to get tested. While an at-home pulse oximeter can be helpful in certain situations, it has limitations and only shows one small aspect of your health. Do not rely on an oximeter to determine a COVID-19 diagnosis.

If you’re experiencing symptoms of COVID-19, contact your healthcare provider as soon as possible.

What are the symptoms of not enough oxygen in the blood?

Symptoms of low blood oxygen levels (hypoxemia) vary depending on the severity of the condition and from person to person. They include:

  • Headache.
  • Shortness of breath.
  • Fast heartbeat.
  • Coughing.
  • Wheezing.
  • Confusion.
  • A bluish color in your skin, fingernails and/or lips.
  • Cherry red color in your skin, fingernails and/or lips (a sign of carbon monoxide poisoning).

A note from Cleveland Clinic

Unless you have an underlying health condition that can affect your body’s ability to take in oxygen, it’s not necessary to regularly monitor your blood oxygen level. While using an at-home pulse oximeter can be helpful in certain situations, it’s not as accurate as a blood test to check your blood oxygen levels. If you experience symptoms of low blood oxygen levels or having trouble breathing, be sure to contact your healthcare provider as soon as possible.

Blood Oxygen Level: What It Is & How To Increase It (2024)


How can I increase my blood oxygen level quickly? ›

In the immediate short term:
  1. Stand or sit up straight. Rather than lying down, which may put pressure on your lungs and make it harder to breathe.
  2. Cough. If you have a cold or the flu, difficulty breathing can decrease oxygen saturation in your blood. ...
  3. Go outside. ...
  4. Drink lots of water. ...
  5. Take slow, deep breaths.
Nov 17, 2021

How can I increase my blood oxygen at home? ›

Breathing air with a higher concentration of oxygen than normal can increase the amount of oxygen in your blood. This makes it easier to carry out activities and may reduce your symptoms.

What vitamin puts oxygen in the blood? ›

B Vitamins

What is does: These vitamins, which include B1, B2, B6, B12, niacin, biotin, folic acid and pantothenic acid, help make energy and red blood cells that carry oxygen to different parts of your body.

Does drinking water increase oxygen in the body? ›

Drink Lots of Water

Drinking lots of water ensures that your lungs stay adequately hydrated, which in turn improves their ability to oxygenate and expel carbon dioxide. Therefore, the oxygen saturation level of your body improves.

What foods boost oxygen level? ›

"Foods that are rich in iron and nitrates are the key to increasing oxygen supply throughout your body. So, beetroot, leafy vegetables, pomegranate, garlic, cabbage, cauliflower, sprouts, meat, nuts and seeds help.

What is normal oxygen level by age? ›

Blood Oxygen Levels by Age Using a Pulse Oximetry Chart
ConditionsBy AgeSpO2
NormalAdults & Children95% to 100%
Normal>70 years oldabout 95%
Brain is affectedAdults & Children80% to 85%
CyanosisAdults & ChildrenBelow 67%
Dec 21, 2022

At what oxygen level should you go to the hospital? ›

90% or less This oxygen level is very concerning and may indicate a severe medical problem. Call 911 or go to the nearest emergency room immediately.

What oxygen level is too low? ›

People should contact a health care provider if their oxygen saturation readings drop below 92%, as it may be a sign of hypoxia, a condition in which not enough oxygen reaches the body's tissues. If blood oxygen saturation levels fall to 88% or lower, seek immediate medical attention, says Dr. Lutchmansingh.

Can vitamin D increase oxygen levels? ›

Vitamin D is an essential part of a healthy diet, as this important nutrient is responsible for immune and bone health, cancer prevention, and improved oxygen levels.

Does B12 increase blood oxygen? ›

Vitamin B12 deficiency anemia is a condition in which your body does not have enough healthy red blood cells, due to a lack (deficiency) of vitamin B12. This vitamin is needed to make red blood cells, which carry oxygen to all parts of your body.

What vitamin deficiency causes low blood oxygen? ›

Vitamin B12 or folate deficiency anaemia occurs when a lack of either of these vitamins affects the body's ability to produce fully functioning red blood cells. Red blood cells carry oxygen around the body.

What to do if oxygen level is below 90? ›

Low oxygen level, also called hypoxemia, is considered a reading between 90% and 92%. A reading this low means you might need supplemental oxygen or that there may be challenges that affect how your lungs function. A result below 90% indicates that you should seek medical attention.

Can being dehydrated make your oxygen level low? ›

Low blood volume shock (hypovolemic shock).

This is one of the most serious, and sometimes life-threatening, complications of dehydration. It occurs when low blood volume causes a drop in blood pressure and a drop in the amount of oxygen in your body.

How long can someone live with low oxygen saturation? ›

Most people will die within 10 minutes of total oxygen deprivation. Those in poor health often die much sooner. Some people may suffer other medical catastrophes, such as a heart attack, in response to oxygen deprivation.

What drink is good for oxygen? ›

You should drink beetroot juice and carrot juice in addition to drinking plenty of water daily to improve your oxygen levels. Beetroot and carrot contain iron which boosts the production of haemoglobin, the blood's oxygen carrier.

Does zinc increase oxygen level? ›

Zinc binds to haemoglobin and increases oxygen affinity2,3.

Which finger is most accurate for pulse oximeter? ›

Which finger is best for the pulse oximeter? The right middle finger and right thumb have statistically higher value, making them perfect for a pulse oximeter. Is 94 blood oxygen level low? Any reading between 94 - 99 or higher reflects normal oxygen saturation.

Why am I short of breath but my oxygen saturation is good? ›

Shortness of breath does not equal saturation (SaO2%)

In other words, your level of dyspnea, or air hunger, does not always correlate with your oxygen saturation. This means that you can be short of breath, even extremely short of breath, even in the presence of normal oxygen saturation.

What to do if oxygen level is 88? ›

If it's at 88% or lower, get to the nearest emergency room as soon as possible. If you have a chronic lung condition, such as COPD or asthma, you'll likely need to see your healthcare provider regularly to make sure your treatment is working.

What happens if your oxygen level is 85? ›

If the oxygen saturation drops below 85%, the severe lack of oxygen affects the brain. The person may experience vision changes and lose consciousness. Severe Hypoxemia: When the blood oxygen levels drop below 80%, the brain, liver, and other vital body organs get affected.

What is the most common cause of low blood oxygen? ›

Lung diseases such as chronic obstructive pulmonary disease (COPD), emphysema, bronchitis, pneumonia, and pulmonary edema (fluid in the lungs) Strong pain medicines and other drugs that hold back breathing. Heart problems. Anemia (a low number of red blood cells, which carry oxygen)

What are signs of lack of oxygen to the brain? ›

Symptoms of mild cerebral hypoxia are:
  • Having a hard time paying attention.
  • Poor judgment and decision making.
  • Memory loss.
  • Having a hard time controlling movement.
  • A change in skin color and/to the lips.
Jan 23, 2023

Is 92 blood oxygen level OK? ›

If you are using an at-home oximeter, you should contact your health care provider if your oxygen saturation level is 92 percent or lower. If it falls to 88 percent or lower, seek immediate medical attention.

Is 88 oxygen level bad? ›

Healthy pulse oximeter values often range from 95% to 100%. Values under 90% are considered low. Often, hypoxemia treatment involves receiving extra oxygen. This treatment is called supplemental oxygen or oxygen therapy.

Does vitamin C increase oxygen in the blood? ›

In addition, under increasing oxygen levels, vitamin C increased the gene expression of BCL2, an antiapoptotic regulator, and decreased the gene expression of TP53, a proapoptotic factor, and the ratio of BAX/BCL2 mRNA, an apoptotic index.

What vitamin deficiency can cause breathing problems? ›

Vitamin D deficiency causes deficits in lung function and alters lung structure.

How much B12 should I take to raise my blood levels? ›

To raise your vitamin B12 level, you have to take at least 1,000 mcg of vitamin B12 every day. Over-the-counter multivitamins do not have this much vitamin B12. To get enough vitamin B12, you will need to take special vitamin B12 pills. You can also get shots of vitamin B12.

What vitamin is best for blood circulation? ›

Top Vitamins for Healthy Circulation
  • B-Complex Vitamins. Vitamin B deficiency can harm your health in many ways, including circulation. ...
  • Potassium (Vitamin K) Potassium is an essential mineral for many important bodily functions, including blood circulation. ...
  • Vitamin C. ...
  • Vitamin E.

Can iron help blood oxygen? ›

Iron is an important mineral for our health because its primary function is to carry oxygen in the blood to every cell in our body via hemoglobin. If your body doesn't have enough iron, it can't produce enough healthy oxygen-carrying red blood cells – which can lead to anemia.

What supplements help low oxygen? ›

Supplements that can help increase blood oxygen levels
  • i). Iron: Iron is an essential mineral that is vital for the production of hemoglobin. ...
  • iii). Vitamin C: Vitamin C, or ascorbic acid, is an essential nutrient that produces collagen, which supports the structure of blood vessels in the body. ...
  • iv). CoQ10: ...
  • v). Niacin:
Mar 23, 2023

What are the two main causes of oxygen deficiency? ›

There are a variety of causes that lead to oxygen deficiency. Leaking materials from storage tanks, natural gas lines, process valves and more release gas that displaces oxygen in poorly ventilated areas or confined spaces.

Which fruit is rich in vitamin B12? ›

Apples Aside from being an important inclusion in a list of vitamin B12 fruits, apples are also rich in fibre, antioxidants, and flavonoids. Apples also comprise polyphenols that are found in both the peel and the pulp of the nutrient-dense fruit.

Can heart blockage cause low oxygen levels? ›

The buildup of plaque limits the flow of blood to the heart, causing a reduction in oxygen. Atherosclerosis can lead to a condition called ischemia, or oxygen starvation of the tissues.

Can drinking water help shortness breath? ›

While it may not be the most common phrase one might be used to seeing and the association isn't immediately clear, the fact is that good hydration habits make a significant positive impact on our ability to breathe well.

What are 2 warning signs of dehydration? ›

Two early signs of dehydration are thirst and dark-coloured urine. This is the body's way of trying to increase water intake and decrease water loss. Other symptoms may include: dizziness or light-headedness.

What is a dangerously low oxygen level while sleeping? ›

How Low Can Your Oxygen Levels Go During Sleep?
Blood Oxygen LevelInterpretation
96 to 100%Normal range
93 to 95%Borderline low
89 to 92%Low
88% or lowerDangerously low
Jun 23, 2023

How low can your oxygen level go before you pass out? ›

Shortness of breath, dizziness, and other symptoms may occur. Blood oxygen level usually range from 75–100 mm Hg. If they fall below 60 mm Hg , there may not be enough oxygen reaching the body's vital organs.

Is 92 a good oxygen level? ›

A normal oxygen saturation level ranges between 95 percent and 100 percent. Saturation levels may be somewhat lower and considered acceptable if you have a lung disease such as COPD or pneumonia.

How long can a person live with low oxygen levels? ›

Most people will die within 10 minutes of total oxygen deprivation. Those in poor health often die much sooner. Some people may suffer other medical catastrophes, such as a heart attack, in response to oxygen deprivation.

What to take when oxygen level is low? ›

Supplemental oxygen may be used to treat an ongoing risk of hypoxemia. Oxygen devices vary, but you can expect to get a machine that delivers extra oxygen through a breathing mask or small tube (cannula). You may receive oxygen at home, with a portable machine while you travel, or in the hospital.

Which finger do you use for pulse oximeter? ›

Make sure your hand is warm to the touch. Then rest it on your chest for five minutes. Switch the pulse oximeter on. Then attach the clip of the pulse oximeter to the finger next to your thumb, or your middle finger.

How accurate are finger oximeters? ›

Most pulse oximeters are accurate to within 2% to 4% of the actual blood oxygen saturation level. This means that a pulse oximeter reading may be anywhere from 2% to 4% higher or lower than the actual oxygen level in arterial blood.

How do you know if you're not breathing enough oxygen? ›

A bluish color seen around the mouth, on the inside of the lips, or on the fingernails may happen when a person is not getting as much oxygen as needed. The color of the skin may also appear pale or gray. Grunting. A grunting sound can be heard each time the person exhales.

What is the oxygen saturation level for heart failure? ›

Monitoring and Target Saturation

British Thoracic Society Guideline for oxygen use in adults in healthcare and emergency settings recommended target oxygen saturation of 94% to 98% for AHF patients. This target should be reduced to 88% to 92% if the patient is at risk of hypercapnic respiratory failure.

Is 94 oxygen OK for elderly? ›

What is a Normal Oxygen Level for the Elderly? A normal oxygen saturation level is 97-100% but older adults typically have lower levels than younger adults. If an individual is older than 70, a normal oxygen level for elderly adults may be about 95%, which is acceptable.

What causes low oxygen levels in old age? ›

Introduction. Older people have lower oxygen retention in the supine position during sleep. The reason is hypoventilation due to age-related reduced lung elasticity, depressed respiratory regulation caused by autonomic dysfunction as well as underventilation due to cardiac, lung and brain diseases [1–7].


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