Your body is a fine-tuned machine more complex than the most advanced devices ever invented. Like state-of-the-art computers and high-performance automobiles, body systems don’t work for free. They need energy. So while you can skip breakfast without too many problems, you can’t hold your breath safely for more than a minute or two.

Oxygen provides the fuel that lets you laugh with friends, solve complicated mental tasks, go for an intensive hike or relax with your favorite book. Low blood oxygen levels can impede all of these activities and more.

Understanding Blood Oxygen Levels

What do the terms mean in blood tests and oxygen measurements?

  • Arterial blood gas (ABG): This common blood test is used to check the levels of oxygen in your blood, as well as blood pH and carbon dioxide present.
  • Millimeters of mercury (mm Hg): This type of measurement is taken from the pressure from gases such as oxygen. Test results appear as a number such as 85 mm Hg.
  • Oxygen saturation: This measurement detects how well the hemoglobin in your red blood cells is transporting oxygen through the body. Oxygen saturation always is given as a percentage.

If the levels of oxygen in your blood fall too low, this condition is called hypoxemia. It doesn’t take long for hypoxemia to lead to hypoxia, a term that means your body’s tissues and organs are also beginning to run out of oxygen. Hypoxia is a very serious condition.

Healthy Blood Oxygen Levels for Adults

An ideal ABG test reading lies between 75 to 100 mm Hg, with blood saturation levels somewhere between 95 and 100 percent. People who have chronic respiratory problems should consult a health professional to know optimal personal oxygen level targets.

When blood oxygen levels fall below 60 mm Hg or 90 percent saturation, they are considered very low. If this happens, it’s critical to head to the hospital immediately.

Ways Low Oxygen Levels Affects Your Body

Low oxygen levels can have a negative effect on body organs. When your liver, kidneys, heart and other organs do not receive sufficient oxygen for a prolonged amount of time, they become damaged.

What if oxygen drops so low that hypoxia sets in? Without vital oxygen to drive energy production, body processes simply can’t continue, and essential organs — such as the brain, heart, pancreas and liver — start to shut down almost immediately.

The Symptoms of Low Blood Oxygen or Hypoxia

Low blood oxygen produces a number of physical symptoms:

  • Cough
  • Shortness of breath
  • Fast heart rate
  • Accelerated breathing
  • Headache
  • Sweating
  • High blood pressure

As oxygen levels fall, effects can become more severe, and new problems may appear:

  • Blue or bright red skin, lips and fingernails
  • Confusion or difficulty speaking
  • Vision problems
  • Chest pain
  • Wheezing

If you or a loved one notice sudden changes in oxygen levels, have an asthma attack or feel as if you’re choking, it’s best to call 911 immediately.

Checking Your Blood Oxygen Levels

Many people will never need to perform a blood oxygen test. However, if you suspect you may have low blood oxygen, it’s easy for a doctor to include an ABG blood test in a routine checkup to put your mind at ease.

What if you have a respiratory problem, such as a type of chronic obstructive pulmonary disease? In that case, your physician will likely recommend keeping closer tabs on blood oxygen levels. You can do this at home using a pulse oximeter, a small device that clips to the finger to measure oxygen saturation levels. The results aren’t as accurate as a blood test — many devices have a variance of around 2 percent — but they let you check your results more often and without extracting any blood.

Causes of Poor Blood Oxygen Levels

Low oxygen may point to underlying problems in the heart, lungs or the blood itself. It can also be the result of a respiratory disease, such as bronchitis or pneumonia. Here are other possible causes:

  • Anemia: The body isn’t producing enough red blood cells, or these cells have insufficient levels of hemoglobin.
  • COPD: A condition that includes emphysema and chronic asthma, COPD makes it more difficult to breathe due to increased swelling and mucus production. This reduces oxygen levels.
  • Pulmonary edema: Fluid accumulates in the lungs, preventing them from working properly and reducing their capacity.
  • Heart disease: Because your heart is what drives oxygen-rich blood throughout the body, heart problems lead to reduced oxygen circulation.
  • Sleep apnea: A person with sleep apnea temporarily stops breathing dozens or hundreds of times during the night. This can lead to periods of damaging hypoxia.

Besides these physical causes, certain circumstances can lead to lower blood oxygen, such as visiting high-altitude locations, recently recovering from surgery or going through a pregnancy. Also, certain prescription medicines may cause lower oxygen saturation as a side effect.

Treating or Preventing Hypoxia and Low Blood Oxygen

There are many medical options for improving your blood oxygen levels, ranging from long-term oxygen supplementation treatments with an oxygen mask to emergency breathing restoration involving bronchodilators (inhalers) or corticosteroids to fight inflammation.

Aside from medical treatments, there are several natural lifestyle changes that can improve your oxygen levels:

  • Breathe more deeply: Breathing exercises help you to fill your lungs, improving the amount of oxygen available.
  • Improve indoor air quality: Fresh, contaminant-free air is great for asthma, allergies and other respiratory conditions.
  • Don’t smoke: Cigarette smoke, even the secondhand variety, causes long-term damage to the lungs and reduces breathing capacity.
  • Eat iron-rich foods: Iron is essential in creating hemoglobin molecules for oxygen transport. Munching on leafy greens, beans, lentils, and eggs can boost iron levels and prevent anemia.
  • Exercise regularly: A healthy amount of exercise maintains your lungs in optimal condition, increasing the amount of oxygen they supply to the blood.

Taking Good Care of Your Body: Watch Your Blood Oxygen Levels

Your body needs oxygen like plants need sunlight. If you suspect that you may not be getting sufficient oxygen, don’t ignore it. Contact a health professional to request a simple ABG blood test or a painless, noninvasive pulse oximeter test. By keeping an eye on blood oxygen levels, even people with chronic respiratory conditions can enjoy greater comfort and better health.