• A condition in which there is a decrease in the oxygen supply to a tissue. In cancer treatment, the level of hypoxia in a tumor may help predict the response of the tumor to the treatment.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• A condition in which there is low oxygen in the tissues.
  NICHD Pediatric Terminology
  U.S. National Cancer Institute, 2021
• A decrease in the amount of oxygen in the body. Symptoms range from mild (impaired judgment, memory loss, impaired motor coordination) to severe (seizures and coma).
  NCI
  U.S. National Cancer Institute, 2021
• A deficiency in the amount of oxygen reaching the tissues.
  U.S. FDA Glossary
  U.S. Food & Drug Administration, 2021
• Reduction of oxygen supply to tissue below physiological level.
  CRISP Thesaurus
  National Institutes of Health, 2006
• Sub-optimal OXYGEN levels in the ambient air of living organisms.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• When all or part of the body doesn't get enough oxygen.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• A disorder characterized by a decrease in the level of oxygen in the body.
  Common Terminology Criteria for Adverse Events
  U.S. National Institutes of Health, 2021
• Hypoxia, in biology and medicine, condition of the body in which the tissues are starved of oxygen. In its extreme form, where oxygen is entirely absent, the condition is called anoxia. Four types of hypoxia are distinguished in medicine: (1) the hypoxemic type, in which the oxygen pressure in the...
  Encyclopedia Britannica
  Encyclopedia Britannica, Inc., 2025