Other Causes of Low Oxygen Levels

  1. not enough oxygen in the air
  2. inability of the lungs to inhale and send oxygen to all cells and tissues
  3. 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:

  1. asthma
  2. heart diseases, including congenital heart disease. The respiratory and circulatory systems work together to ensure that adequate oxygen is transferred from the lungs to the bloodstream and subsequently delivered to the body. Therefore, problems with the circulatory system that interfere with normal blood flow through the lungs can lead to hypoxemia. Tissue hypoxia, as a result of cardiopulmonary dysfunction or reduced oxygen-carrying capacity, is a frequently encountered clinical problem.[1]
  3. high altitude
  4. anemia: Red blood cells transport oxygen from the lungs to the body organs and tissues via a carrier molecule called hemoglobin. A deficiency of red blood cells, or anemia, limits the oxygen-carrying capacity of the blood, potentially leading to reduced total oxygen content in the bloodstream.
  5. chronic obstructive pulmonary disease or COPD: People who have lung pathologies develop severe ventilation-perfusion mismatch that leads to critically low arterial blood oxygen levels. This effect takes place due to the ability of CO2 to dilate airways (bronchi and bronchioles). Greatly reduced blood oxygenation makes cell oxygen level low as well.
  6. interstitial lung disease
  7. emphysema
  8. acute respiratory distress syndrome or ARDS
  9. pneumonia
  10. obstruction of an artery in the lung, for instance, due to a blood clot
  11. pulmonary fibrosis or scarring and damage to the lungs
  12. presence of air or gas in the chest that makes the lungs collapse
  13. excess fluid in the lungs
  14. sleep apnea where breathing is interrupted during sleep
  15. certain medications, including some narcotics and painkillers.

[1] Kidney Int. 2008 Apr; 73(7): 797–799. Low oxygen stimulates the immune system