Low and normal blood oxygen levels: What to know

  1. How is blood oxygen level measured?
  2. Normal and low blood oxygen levels
  3. Symptoms of low blood oxygen levels
  4. Causes
  5. When to see a doctor
  6. Treatment
  7. Outlook

Blood oxygen level is the amount of oxygen circulating in the blood. Most of the oxygen is carried by red blood cells, which collect oxygen from the lungs and deliver it to all parts of the body.

The body closely monitors blood oxygen levels to keep them within a specific range, so that there is enough oxygen for the needs of every cell in the body.

A person’s blood oxygen level is an indicator of how well the body distributes oxygen from the lungs to the cells, and it can be important for people’s health.

How is blood oxygen level measured?

Blood oxygen levels may be measured using a pulse oximeter.

The most efficient way to monitor blood oxygen levels is by 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 accurate, but it can be a little painful.

An ABG test can be difficult to do at home, so a person may wish to do an alternative test, using a small device known as a pulse oximeter.

A pulse oximeter is a small clip that is often put on a finger, although it can also be used on the ear or toe. It measures blood oxygen indirectly by light absorption through a person’s pulse.

Although the pulse oximeter test is easier, quicker, and not painful, it is not as accurate as the ABG test. This is because it can be influenced by factors such as dirty fingers, bright lights, nail polish, and poor circulation to the extremities.

For people who wish to purchase a pulse oximeter, there is a range of easy-to-use devices available online.

Normal and low blood oxygen levels

A normal blood oxygen level varies between 75 and 100 millimeters of mercury (mm Hg).

A blood oxygen level below 60 mm Hg is considered low and may require oxygen supplementation, depending on a doctor’s decision and the individual case.

When blood oxygen level is too low compared to the average level of a healthy person, it can be a sign of a condition known as hypoxemia. This means that the body has difficulty delivering oxygen to all of its cells, tissues, and organs.

Symptoms of low blood oxygen levels

Shortness of breath and a rapid heartbeat are potential symptoms of low blood oxygen levels.

Low blood oxygen levels can result in abnormal circulation and cause the following symptoms:

shortness of breath




rapid breathing

chest pain


high blood pressure

lack of coordination

visual disorders

sense of euphoria

rapid heartbeat

Pulse oximetry: Uses and benefits
How do pulse oximeters work? Who needs to use one?
Read now


Hypoxemia, or oxygen levels below the normal values, may be caused by:

not enough oxygen in the air

inability of the lungs to inhale and send oxygen to all cells and tissues

inability of the bloodstream to circulate to the lungs, collect oxygen, and transport it around the body

Several medical conditions and situations can contribute to the above factors, including:


heart diseases, including congenital heart disease

high altitude


chronic obstructive pulmonary disease or COPD

interstitial lung disease


acute respiratory distress syndrome or ARDS


obstruction of an artery in the lung, for instance, due to a blood clot

pulmonary fibrosis or scarring and damage to the lungs

presence of air or gas in the chest that makes the lungs collapse

excess fluid in the lungs

sleep apnea where breathing is interrupted during sleep

certain medications, including some narcotics and painkillers

When to see a doctor

People should see a doctor if they:

experience severe and sudden shortness of breath

experience shortness of breath when at rest

have severe shortness of breath that worsens during exercise or physical activity

wake suddenly with shortness of breath or a feeling of choking

are at high altitude (above 8,000 feet or 2,400 meters) and experience severe shortness of breath with a cough, rapid heartbeat, and fluid retention


Quitting smoking and avoiding areas where others are smoking may help to improve low blood oxygen levels.

Treatment for low blood oxygen levels includes receiving supplemental oxygen. This can be done at home when it is called home oxygen therapy or HOT.

There is a range of devices for delivering and monitoring HOT, but some of them are considered medications and need a prescription.

Some self-care measures can be taken by people to reduce symptoms of shortness of breath and improve general health and quality of life. These include:

quitting smoking

avoiding passive smoking in places where others smoke

eating a healthful diet with plenty of fruits and vegetables

exercising regularly


Low oxygen levels in the blood are not necessarily harmful and can occur in people who can recover, or in healthy people when they are at high altitude. These people do not need to monitor their blood oxygen levels regularly.

But people with chronic lung diseases, such as COPD, pulmonary fibrosis, or emphysema, may have blood oxygen levels below the normal because of their illness. These people may require regular blood oxygen monitoring.

People with low blood oxygen can also make lifestyle changes, such as not smoking or improving their diet and exercise habits, as well as being treated with supplemental oxygen.

We pick these items based on the quality of the products, and list the pros and cons of each to help you determine which will work best for you. We partner with some of the companies that sell these products, which means Healthline UK and our partners may receive a portion of revenues if you make a purchase using a link(s) above.


  1. Novak WilfordMarch 6, 2018

    Last year I started on COPD Herbal formula treatment from rich herbs foundation, the treatment worked incredibly for my lungs condition. I used the herbal treatment for almost 5 months, it reversed my COPD. My severe shortness of breath, dry cough, low energy, fatigue, chest tightness and others gradually disappeared. Visit rich herbs foundation via their web-site ww w. richherbsfoundation .com. This COPD treatment has improved the quality of my life greatly, i breath much better and feel comfortable doing so!

  2. Davina ConollyMarch 13, 2018

    After my 3rd pulmonary embolism in 2003, I was diagnosed with pulmonary fibrosis and I read that people usually die within 5 years. My specialist has me on blood thinners, prednisone and other steroids that I inhale daily. October 2006 I decided to go with natural treatment and was introduced to Green House Herbal Clinic natural organic idiopathic pulmonary fibrosis Herbal formula, i had a total decline of symptoms with this pulmonary fibrosis Herbal formula treatment. The infections, shortness of breath, fatigue, dry cough and other symptoms has subsided. Somehow, the herbs managed to keep me alive for 13 years.Visit Green House Herbal Clinic official website I have had great improvement with my over all respiration with this product and i breath very much easier


Leave a Reply

Your email address will not be published.