What is a Normal Blood Oxygen Level by Age?

normal blood oxygen level by age

Your blood oxygen level refers to the amount of oxygen that your red blood cells are carrying throughout your body.

Oxygen is a crucial nutrient that allows your cells and organs to function properly.

As you breathe, oxygen travels into your lungs and then gets absorbed by red blood cells in the lungs’ air sacs known as alveoli.

The oxygenated blood is then pumped from the lungs back to the heart, which pumps it through arteries to deliver oxygen to tissues and cells throughout the body.

Oxygen levels are generally measured as an oxygen saturation percentage, with 100% being the maximum amount of oxygen your blood can hold.

Normal blood oxygen saturation usually ranges from 95-100%.

Levels under 90% are considered low and potentially dangerous if sustained for long periods.

For example, in healthy individuals, hemoglobin proteins in red blood cells are usually saturated with 95-100% oxygen.

This means almost all of the hemoglobin is carrying oxygen to the body’s vital organs and tissues.

Lower saturation means less oxygen is being transported in the bloodstream.

Normal Blood Oxygen Levels by Age Group

While 95-100% is considered the normal range for blood oxygen saturation, there are some variations based on your age and health status. Here are the general target ranges by age:

Infants & Children:

  • Newborns: 95-100%
  • Infants & toddlers: 95-100%
  • Young children: 95-100%

For infants and young kids, maintaining saturations in the 95-100% range is very important, as their bodies and brains are still developing. Levels below 95% can be a cause for concern if sustained over time.

For example, newborn babies normally have oxygen saturations around 95-100%, and levels below 90% can be dangerous if prolonged. Infants who have breathing issues or lung conditions may require supplementary oxygen to keep their levels in a healthy range.


  • 95-100%

For healthy adults, normal oxygen saturation is 95-100%. Levels below 92% may cause issues like shortness of breath or difficulty thinking clearly.

Adults with certain health conditions, like chronic obstructive pulmonary disease (COPD), may have lower normal saturations around 90-95%. Their doctors monitor this closely to ensure adequate oxygen delivery.

Elderly Adults:

  • 90-95%

As we age, oxygen saturation levels tend to decrease slightly. For seniors over 65, normal levels are around 90-95%.

The gradual decline is due to age-related changes in lung function and circulation. Underlying health conditions can also impact oxygen levels.

Chronic lung diseases like COPD and pulmonary fibrosis are common in seniors and can lower oxygen saturation.

Doctors keep a close eye on oxygen levels in elderly patients to watch for drops below 90%, which may require supplemental oxygen for safety.

How to Monitor Your Blood Oxygen Levels

Checking your blood oxygen level regularly is important, especially if you have an underlying medical condition that impacts lung or heart function. Here are some ways to monitor it:

Pulse oximeter:

This small device clips onto your fingertip and uses light beams to estimate oxygen saturation in your blood. Pulse oximeters are easy to find online or in pharmacies for around $20-50.

To use one, simply turn it on and place your finger inside. Keep your hand still for 30 seconds to get a reading. Make sure to follow the product directions for most accurate results.

Pulse oximeters allow you to quickly check your levels at home between doctor visits. This helps identify any major drops that may require medical attention.

Arterial blood gas (ABG) test:

For a more precise measurement, an ABG test samples oxygen levels directly from your blood.

A healthcare provider will use a needle to draw blood from an artery, usually in your wrist. The blood is analyzed to determine precise oxygen and carbon dioxide levels.

Because it’s invasive, ABG testing is usually done only when very accurate results are needed, like in hospital ICUs and operating rooms. It also helps evaluate lung function in people with respiratory diseases like COPD.

Overnight oximetry study:

If you have a condition like sleep apnea, your doctor may order an overnight oximetry study. This involves wearing a pulse oximeter device overnight while you sleep to track your trends in blood oxygen.

The detailed data helps identify significant desaturation events that may occur during sleep apnea episodes. Doctors can then better tailor treatments to optimize your overnight oxygen levels.

Supplemental oxygen monitoring:

For patients requiring long-term supplemental oxygen, like those with severe COPD, oxygen saturation is monitored continuously or periodically using blood tests or pulse oximeters. This helps ensure the prescribed oxygen therapy is maintaining safe blood oxygen levels.

Proper monitoring allows doctors to adjust oxygen flow rates and devices as needed to keep levels in the target range for each patient based on their condition.

How to Maintain Healthy Blood Oxygen Levels

Here are some lifestyle habits and tips that can help support healthy oxygen saturation levels:

Don’t smoke and avoid secondhand smoke. Smoking damages lung tissue over time, making it harder to breathe and get adequate oxygen into the blood.

Exposure to secondhand smoke can also reduce oxygen saturation. Quitting smoking is one of the best things you can do for your lung health and oxygen levels.

Exercise regularly. Aerobic exercise improves lung capacity and function, allowing you to take in more oxygen.

Aim for at least 150 minutes of moderate exercise like brisk walking per week to reap the benefits. Start slow if you have an underlying condition.

Maintain a healthy weight. Excess weight can hamper breathing and oxygen circulation. Losing weight if you are obese or overweight can help reduce shortness of breath and keep oxygen levels in normal ranges.

Manage chronic lung and heart disease. Follow your doctor’s treatment plans for conditions like COPD, asthma, heart failure or sleep apnea.

Properly managing these diseases can help prevent severe drops in blood oxygen.

Avoid high altitudes. The air at high altitudes contains less oxygen, which can lower oxygen saturation. People with lung conditions should use caution when traveling to higher elevations.

Practice deep breathing exercises. Deep breathing techniques can help maximize your oxygen intake to support saturation levels. Try yoga breathing or abdominal breathing techniques.

Use supplemental oxygen as prescribed. If you have chronically low oxygen levels, use prescribed supplemental oxygen as directed to help keep your levels up. Proper use is key to getting the benefits.

Get regular blood oxygen checks. Monitor your levels with at-home pulse oximeters and follow up with your doctor at advised intervals to help catch any abnormalities early.


What causes low blood oxygen levels?

There are several potential causes of low oxygen saturation levels (hypoxemia) including:

  • Lung diseases – Conditions like COPD, pneumonia, pulmonary embolism, and fibrosis can impair gas exchange in the lungs and lower oxygen absorption into the bloodstream.
  • Heart failure or disorders – Weakened heart muscle as in heart failure reduces blood circulation, while heart defects present from birth can alter blood oxygenation.
  • Anemia – Having a low red blood cell count reduces the blood’s oxygen-carrying capacity.
  • Obesity – Excess weight impairs breathing and oxygen circulation.
  • Sleep apnea – Interrupted nighttime breathing lowers oxygen.
  • High altitude – Thinner air at high elevations contains less oxygen.
  • Infection – Lung infections like pneumonia interfere with oxygen uptake.

What are the symptoms of low blood oxygen levels?

Here are some possible signs of low oxygen saturation:

  • Shortness of breath
  • Rapid, shallow breathing
  • Fatigue/weakness
  • Headaches
  • Dizziness/lightheadedness
  • Chest pain or tightness
  • Fast heart rate
  • Cough
  • Cyanosis – blue tinging of skin, lips or nail beds
  • Impaired mental function/confusion
  • Nausea

Symptoms may develop gradually or come on suddenly, depending on the underlying cause. Call 911 or seek emergency care if you experience severe shortness of breath, high fever, sudden confusion or blurry vision.

Can low blood oxygen levels be treated?

Yes, low oxygen levels can often be treated through a variety of interventions:

  • Prescribed supplemental oxygen – Delivered through nasal cannula, face mask or hyperbaric chamber.
  • Mechanical ventilation – Machine breathing assistance for severely low oxygen.
  • Treating the underlying condition – This may include antibiotics for lung infections, inhalers for COPD, diuretics for heart failure, etc.
  • Surgery – To repair heart defects or remove blood clots, for example.
  • Anemia treatments – Iron supplements, diet changes, medication.
  • CPAP machine for sleep apnea – Keeps airway open to maintain nighttime oxygen levels.
  • Steroids – To reduce lung inflammation in conditions like COPD exacerbations or pneumonia.
  • High-altitude acclimatization – Gradual exposure to high elevations allows the body to adjust to lower oxygen levels.

The specific treatments used will depend on the cause and severity of low oxygen levels for each patient. Prompt medical treatment is key.

What is a normal blood oxygen level for a healthy adult?

For healthy adults, normal arterial blood oxygen saturation is 95-100%. Levels below 92% are considered low and may cause issues like shortness of breath.

Health experts consider oxygen levels below 90% dangerously low for most adults, since the body’s organs and tissues need adequate oxygen to function properly.

Can stress or anxiety affect blood oxygen levels?

Yes, anxiety and stress can sometimes lower oxygen saturation temporarily. Stress triggers your sympathetic nervous system, which controls your fight-or-flight response. This can cause breathing changes, increased heart rate, and constricted blood vessels.

Rapid, shallow breathing brought on by anxiety may prevent you from taking slow, deep breaths to fully oxygenate your blood. Excess oxygen consumption from a racing heart can also reduce oxygen levels.

The drops are usually short-term and resolve once the stress response decreases. But chronically high anxiety could potentially impact oxygen levels more severely. Relaxation techniques like deep breathing may help counteract this.

Can sleep apnea cause low blood oxygen levels?

Sleep apnea commonly causes low blood oxygen levels at night. This sleep disorder causes your throat muscles to relax and temporarily block airflow during sleep. These interrupted breaths lower oxygen, often many times per hour.

In one study, around 98% of people with sleep apnea were found to have abnormally low oxygen saturations at night. Dangerously low levels below 80% may occur with severe apnea cases.

Treatments like CPAP machines, oral appliances, or surgery can help restore normal breathing and oxygen levels during sleep for apnea patients.

What are the long-term effects of chronically low blood oxygen?

Prolonged low oxygen levels in the blood (chronic hypoxemia) can result in:

  • Pulmonary hypertension – Increased blood pressure damages lung arteries.
  • Heart problems – Strained right ventricle, heart failure, arrhythmias.
  • Cognitive impairment – Memory loss, dementia due to brain cell damage.
  • Leg swelling – Fluid buildup from poor heart circulation.
  • Vision loss – Retinal damage.
  • Reduced immune function – Inability to fight infections.
  • Fatigue and weakness – Decreased oxygen to muscles.
  • Mood changes – Anxiety, depression.
  • Poor wound healing – Lack of oxygen impairs cell repair.

That’s why it’s critical to treat the underlying causes of any chronic low oxygen and maintain levels in a healthy range.

Can breathing exercises help improve blood oxygen levels?

Yes, certain breathing techniques can temporarily help boost low oxygen saturation levels through the following mechanisms:

  • Deep, diaphragmatic breathing maximizes air intake and lung expansion, allowing more oxygen to enter the bloodstream from the lungs.
  • Controlled breathing can reduce anxiety and prevent rapid shallow breaths that impair oxygen uptake.
  • Exhalation breathing exercises help clear mucus from airways to enhance lung efficiency.
  • Alternate nostril breathing may induce relaxation, reducing oxygen demand.

However, breathing exercises alone are not an adequate treatment for chronically low oxygen caused by lung/heart disease or sleep apnea. Medical treatments are still needed in those cases to address the underlying issues. Discuss starting any new breathing regimen with your doctor first.