Hypoxia: Symptoms & Signs

Medically Reviewed on 3/15/2021

Hypoxia refers to a condition in which oxygen levels are too low.

Signs and symptoms of hypoxia vary according to the severity of the condition and whether it arises suddenly or comes on gradually over time. Associated signs and symptoms can include

Causes of hypoxia

There are many possible causes of hypoxia, including environmental conditions with low oxygen (like high altitude), lung diseases (including asthma, chronic obstructive pulmonary disease, lung cancer, pneumothorax), heart diseases (including arrhythmia, heart defects, or heart attack), drowning, chemical or gas poisoning, trauma or injury, certain medications that reduce the rate of breathing, and anemia or conditions that destroy red blood cells.

Other hypoxia symptoms and signs

  • Bluish Color (Cyanosis) in the Skin, Fingernails, and Lips
  • Confusion
  • Coughing
  • Fast Heartbeat
  • Headache
  • Shortness of Breath
  • Wheezing


COPD (chronic obstructive pulmonary disease) is the same as adult-onset asthma. See Answer

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Jameson, J. Larry, et al. Harrison's Principles of Internal Medicine, 20th Ed. New York: McGraw-Hill Education, 2018.