Understanding Normal and Low Blood Oxygen Levels

Understanding Normal and Low Blood Oxygen Levels

If you have a heart or lung condition, your doctor may have recommended that you regularly check your blood oxygen levels. This may have prompted you to wonder what blood oxygen levels are.

Blood oxygen levels, also known as oxygen saturation, refers to the amount of oxygen present in the blood. The red blood cells are responsible for transporting oxygen to all vital organs in the body. The level of oxygen in the blood can indicate how effectively oxygen is being distributed throughout the body from the lungs.

When measuring blood oxygen levels with a pulse oximeter, normal levels typically range from 95-100%. Oxygen levels below 90% may be considered low and may require oxygen supplementation.

A low blood oxygen level is indicative of hypoxemia, a condition in which the body struggles to supply oxygen to all organs, cells, and tissues.

Causes of low oxygen levels:

There are various factors that can lead to low oxygen levels, such as:

  • An ongoing heart condition
  • Allergic reactions
  • Sleep apnea
  • Suffocation or choking
  • Traveling to places situated at higher altitudes
  • Infections such as pneumonia and viruses such as Covid-19
  • Certain medications including some painkillers

If you experience the following symptoms, you should contact a doctor for a home visit:

  • Shortness of breath, even when at rest
  • Rapid breathing or chest pain
  • Waking up feeling as though you are choking


Treatment for low oxygen levels typically includes supplementary oxygen, also known as Home Oxygen Therapy (HOT). If you are unsure about how to proceed, it is best to contact a home-based healthcare provider for assistance.