Blood Oxygen Levels: What Is A Normal Level? - Healthline

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Is My Blood Oxygen Level Normal?

Medically reviewed by Danielle Hildreth, RN, CPT — Written by Kimberly Holland — Updated on June 29, 2023

Results
Symptoms
Causes
Treatment
FAQs
Takeaway

A healthy blood oxygen level is 75–100 mm Hg, or 95–100%. Low blood oxygen levels, known as hypoxemia, may be a cause for concern.

Your blood oxygen level is a measure of how much oxygen your red blood cells are carrying.

Most children and adults don’t need to monitor their blood oxygen levels. Many doctors won’t check it unless you’re having a procedure done or show signs of problems like shortness of breath or chest pain.

People with certain health conditions may need to monitor their blood oxygen levels to determine whether treatments are working or need to be adjusted.

These conditions might include:

asthma
heart disease
chronic obstructive pulmonary disease (COPD)
cystic fibrosis

There are two types of tests used to measure blood oxygen levels: pulse oximeter and arterial blood gas (ABG). A pulse oximeter may be used at home or at a medical office. ABG, while very accurate, requires a blood sample to be taken by a healthcare professional.

Keep reading to learn more about measurements, causes, and treatments for low blood oxygen levels.

Understanding your blood oxygen level readings

Your results may vary depending on the type of test used to measure your blood oxygen levels.

A pulse oximeter reading indicates what percentage of your blood is saturated, known as the SpO2 level. A typical, healthy reading is 95–100%. If your SpO2 level is less than 92%, a doctor may recommend you get an ABG.

A pulse ox is the most common type of test because it’s noninvasive and provides quick readings. However, FDA-approved pulse oximeters may have a 2–3% error window when compared with ABG values.

An ABG measurement will determine the partial pressure of oxygen in your blood, known as PaO2. A normal ABG oxygen level for healthy lungs is between 75 and 100 millimeters of mercury (mm Hg).

This test is very accurate but more invasive.

People who smoke may also need an ABG test as they might have an inaccurately high pulse ox reading. Smoking causes carbon monoxide to build up in your blood. A pulse ox can’t tell the difference between this type of gas and oxygen.

Arterial blood gas (ABG)	Pulse oximeter
Healthy level	75–100 mm Hg	95–100%
When to get medical help	less than 74 mm Hg	less than 95%

These ranges may differ for people with COPD or other lung diseases. If you are living with a lung condition, discuss your levels with your doctor. They can help you identify what a normal range will look like for you.

Symptoms of low blood oxygen levels

When your blood oxygen level goes below 95%, you’re at risk of hypoxemia. Hypoxemia is the medical term for low blood oxygen levels.

This is often cause for concern, as it may lead to complications that affect the brain, kidneys, or heart.

You may experience symptoms like:

shortness of breath
chest pain
coughing or wheezing
confusion
headache
rapid heartbeat

If your blood oxygen level falls below 80–85%, visual and cognitive changes may start to develop.

At 67%, you’re at risk of developing symptoms of cyanosis. The hallmark sign of this is a blue discoloration of your nail beds, skin, and mucus membranes.

Cyanosis may also lead to respiratory failure, which can be life threatening. If you’re experiencing symptoms, get medical attention immediately.

It’s important to know what your regular oxygen level is, especially if you have a chronic lung condition. A doctor may provide recommendations as to what range of oxygen levels are acceptable for you.

Causes of low blood oxygen levels

Certain health conditions may cause hypoxemia by affecting your lung function. Some of these include:

COPD, including chronic bronchitis and emphysema
acute respiratory distress syndrome
asthma
collapsed lung
pneumonia
anemia
congenital heart defects
heart disease
pulmonary embolism

Blood disorders and problems with your circulatory system may also prevent your blood from picking up oxygen and transporting it throughout your body.

The ways in which these conditions and disorders lower your blood oxygen levels can be classified in five different ways:

ventilation/perfusion (V/Q) mismatch
shunt
diffusion impairment
hypoventilation
low environmental oxygen, which typically occurs at high altitudes

Increasing blood oxygen levels

Home remedies

There are several ways to increase your blood oxygen levels at home naturally. Options include:

pursed lip breathing
belly breathing
walking outside
allowing fresh air into your home
having houseplants
quitting smoking or avoiding secondhand smoke
exercising regularly
eating a well-balanced diet

Oxygen saturation

If your blood oxygen level is too low, you may need supplemental oxygen to boost your oxygen saturation.

Home supplemental oxygen is a medication, and a doctor must prescribe it. It’s important to follow their advice on how home oxygen should be used to avoid complications.

Frequently asked questions

Is 92% a good oxygen level?

In most people, a healthy blood oxygen level is 95–100%. Anything below 95% is considered low and may put you at risk of hypoxemia.

That said, people with certain conditions, such as COPD, may need to maintain their blood oxygen at a different level.

Speak with a doctor to determine the ideal or realistic level for you.

At what oxygen level should I be concerned?

A blood oxygen level below 95% is considered low and may put you at risk of hypoxemia.

Symptoms of low blood oxygen levels include:

shortness of breath
chest pain
coughing or wheezing
confusion
headache
rapid heartbeat
a blue discoloration of your nail beds, skin, and mucus membranes

If you’re experiencing any of these symptoms, get immediate medical attention.

Is it OK if your oxygen level is 94?

A blood oxygen level below 95% is considered low. But, a pulse oximeter might have a 2–3% margin of error. If you’re concerned about your blood oxygen level, an ABG test may provide a more accurate measurement.

Takeaway

Maintaining a blood oxygen level of 75–100 mm Hg or 95–100% is vital for a healthy heart, brain, and kidneys. Most people don’t need to monitor their blood oxygen levels regularly.

But if you have a health condition that may cause low oxygen states, measuring your levels with pulse oximetry is noninvasive and quick.

How we reviewed this article:

SourcesHistoryHealthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

Castro D, et al. (2022). Arterial blood gas.https://www.ncbi.nlm.nih.gov/books/NBK536919/
Hafen BB, et al. (2022). Oxygen saturation. https://www.ncbi.nlm.nih.gov/books/NBK525974/
Oxygen level tests. (2022). https://www.asthmaandlung.org.uk/symptoms-tests-treatments/tests/oxygen-level-tests
Pulse oximeter accuracy and limitations: FDA safety communication. (2022). https://www.fda.gov/medical-devices/safety-communications/pulse-oximeter-accuracy-and-limitations-fda-safety-communication
Sarkar M, et al. (2017). Mechanisms of hypoxemia. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5234199/

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Medically reviewed by Danielle Hildreth, RN, CPT — Written by Kimberly Holland — Updated on June 29, 2023

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