Understanding What Is a Normal Spo2 Level and How It Changes during Sleep and Exercise

Understanding What Is a Normal Spo2 Level and How It Changes during Sleep and ExerciseSpO2 (oxygen saturation) measures the amount of oxygen in the blood. The body needs oxygen to maintain healthy cells and organs. Critical organs like the brain can suffer significantly without sufficient oxygen. Therefore, maintaining normal SpO2 levels is a necessity. So what is the normal SpO2 level?

Normal SpO2 (oxygen saturation) levels is usually between 95–100% for adults and children. SpO2 level below 95% is considered abnormal. Changes in the brain (e.g., cognitive, visual, and electrical activity) occur when SpO2 levels fall below 80–85%.

When SpO2 levels drop to about 67%, the skin and mucous membrane turn bluish, a condition called cyanosis. However, it’s common for older adults to have lower oxygen saturation levels than children and younger adults.

For example, those over 70 years old might have oxygen levels near 95%. This is okay for that age group. However, the normal oxygen saturation rate for children and infants is 97% or higher.

Low oxygen in body tissues is referred to as hypoxia, whereas low oxygen in the blood is hypoxemia. Both conditions can crop up individually. However, they may occur together because tissues get insufficient oxygen supply when the oxygen saturation in the blood is low. Anyone can use pulse oximeters to measure SpO2 levels at home.

What Is Normal Spo2 Level When Sleeping?

During sleep, normal SpO2 levels should be at 95%. Although it’s normal for your blood oxygen levels to drop when sleeping, levels below 90% indicate hypoxemia.

Body functions differ during sleep, says WebMD. That includes breathing, heart rate, blood pressure, and blood flow. A person’s blood oxygen level is lower during REM sleep as their breathing becomes shallower and more irregular.

There is a strong link between sleep-related breathing problems and chronic heart diseases and mental illnesses. One study shows that the risk of depression doubles when the average value of blood oxygen level falls below 90% oxygen during sleep.

Causes and Risk Factors of Low Oxygen Levels

According to the Cleveland Clinic, mild lung disease and sleep apnea may lead to nocturnal hypoxemia or a drop in blood oxygen levels during slumber. High altitudes may also contribute to this condition, which is why breathing on top of a mountain may be more difficult.

Obstructive apnea causes pauses in breathing that commonly last 10 to 30 seconds and up to a minute or longer in more sever cases. According to the American Academy of Sleep Medicine, not breathing for over 30 seconds during sleep will cause a individual’s blood oxygen level to drop abruptly. It can fall by as much as 40% or more in severe cases.

Other health conditions can also lead to hypoxemia. The list includes anemia, asthma, acute respiratory distress syndrome, blood clot in the lung, pneumonia, and pulmonary embolism, among others. People with any of these health conditions should consider tracking their SpO2 levels with pulse oximetry.

Blood oxygen level below 90% is dangerous to the body organs and call for immediate intervention. The brain can survive only four minutes without oxygen. Other organs such as the liver, kidney, lung, and heart may have limited or no function when oxygen levels drop below normal. The lower the blood oxygen level, the higher the risk of organ damage.

Symptoms of Low Oxygen Levels

Low blood oxygen levels cause abnormal circulation, which leads to the following symptoms:

  • Dizziness
  • Headaches
  • Restlessness
  • Shortness of breath accompanied by chest pains
  • Rapid breathing
  • High blood pressure (hypertension)
  • Confusion

Health Consequences of Low Oxygen Levels

Normal blood oxygen level is essential for proper organ function. According Medical News Today, hypoxemia can lead to the following complications:

  • Brain damage
  • Brain death
  • Heart problems
  • Lung complications
  • Kidney problems

Knowing and treating the root cause of low blood oxygen level during sleep is essential to cure the problem.

What Is the Normal SpO2 Level When Exercising?

As a general rule, oxygen levels should be at 95%–100% to be normal. However, it can drop during exercise. Medical intervention may be necessary if oxygen levels fall to 86%–90% constantly. Low oxygen saturation makes the heart strain and breathing strenuous and reduces your energy levels. With low energy, exercising becomes more challenging or impossible.

The Effect of Exercise on SpO2 Levels

The average oxygen saturation levels generally remain unaffected when having moderate exercise. However, high-intensity workouts force the body to produce more energy, a process that requires oxygen. This leads to breathing more rapidly to satisfy the body’s demand for more oxygen.

Blood oxygen levels may drop by about 2–3% during more vigorous exercise, falling as low as 92%. However, after exercise, everything will return to normal, and oxygen saturation will go into recovery mode. Recovery will occur more rapidly for people in better shape.

Why Does Oxygen Drop during Exercise?

Oxygen levels fall during exercise because the muscles uses more energy, which requires more oxygen to make. Your breathing speeds up from 15 times per minute (12 liters of air) when at rest to 40–60 times a minute (100 liters of air) to cope with the higher demand for oxygen during exercise, according to Breathe (Sheff).

Measuring Pulse during Exercise

Anyone can use an exercise pulse oximeter to measure oxygen levels in the blood during workout. Many athletes and people with health issues use pulse oximeters when working out or doing moderate to intense physical activities. People who regularly engage in vigorous workouts, especially in high altitudes, will benefit greatly from pulse oximetry during exercise.

Patients recuperating from surgery or with respiratory diseases should also consider wearing a portable pulse oximeter during exercise to track their SpO2 levels.

When the levels are high, the muscle cells will have a short recovery period. When the blood oxygen level is low, a person may feel worn out more quickly and not have the best exercise.

Pulse oximeters are the best option for determining the oxygen level in the blood during exercise, but there are other ways to measure SpO2 during workouts. For example, there are apps that measure blood oxygen levels using the phone’s rear camera and flashlight. Some fitness trackers also have a similar feature.

Without pulse oximetry, one can observe physical signs and symptoms that may indicate low blood oxygen levels during exercise. These include shortness of breath, dizziness, and loss or dimming of sight. Stop exercising right away if these symptoms occur to avoid a life-threatening situation.

One can maintain healthy blood oxygen levels by working out appropriately and breathing adequately through exercise. Maintaining blood oxygen saturation at optimum levels while working out is essential to getting good exercise.

How to Increase Blood Oxygen Level

Here are several ways to improve oxygen saturation.

Get Enough Fresh Air

Keep windows open to let air flow indoors, and engage in hobbies or physical activities that allows you to spend time outdoors. Enjoy the fresh air that introduces sufficient amounts of oxygen to the body and supports high energy production and rapid recovery.

Eat Iron-Rich Foods

Iron is vital for creating hemoglobin, a protein in red blood cells that enables them to transport oxygen throughout the body. Without iron, the body and its organs don’t get the oxygen it needs.

Watch out for symptoms of iron deficiency, such as general fatigue, weakness, pale skin, shortness of breath, dizziness, cravings for junk food, tinging feeling in the legs and tongue swelling and soreness.

Add lots of iron-rich food to your diet. Green vegetables like spinach and kale are rich in iron/ There are also supplements you can take advantage of to complement your diet. However, always consult your healthcare provider first before taking any iron supplements.

Drink Plenty Of Water

Staying hydrated allows the lungs to do a better job of distributing oxygen to the bloodstream. Drinking plenty of water is generally good for the body.

Quit Smoking

Cigarettes contain carbon monoxide, which limits the quantity of oxygen in the body by binding to the hemoglobin in red blood cells, preventing oxygen from attaching to it. Tar in tobacco damages the small tubes in lungs that absorb oxygen and the small hairs (cilia) that protect the organ from debris and infection.

Breathing Exercises

Breathing exercises are essential for increasing your oxygen levels. You can improve oxygen saturation levels at any time by practicing deep slow breathing, as in the case of yoga.

You can practice breathing techniques such as the 4-7-8 technique, or “relaxing breath,” which can significantly improve your oxygen saturation. Inhale for 4 seconds, hold for 7 seconds, then exhale for 8 seconds to complete the exercise and repeat several times daily. The goal of this breathing technique is to assist individuals in relaxing or falling asleep. It can put individuals to sleep in only one minute.

Then exhale for eight counts and do it again. Practice this several times daily, and you will notice your oxygen levels improving in your daily life and during your vigorous workouts.

Bottom Line

Blood oxygen level is the amount of oxygen flowing in the blood. You can use a pulse oximeter to measure your blood oxygen levels. Oxygen levels under 95% are considered to be low.

Some conditions that can lead to low blood oxygen levels include anemia, asthma, COVID-19, and respiratory and cardiovascular diseases.

The treatment usually involves dealing with the root cause. However, doctors may also advise oxygen therapy and lifestyle changes.