When a patient has hypoxia, some area of their body doesn't get enough oxygen. One of the symptoms of hypoxia is discolored skin, which can appear either bluish or bright red.
There are many causes of hypoxia, which can affect either the entire body or just specific organs. Premature babies frequently suffer from hypoxia because their lungs are underdeveloped, and both mountain climbers and scuba divers are also at risk of developing hypoxia. When it occurs at high altitudes, hypoxia is called "altitude sickness." Hypoxia was coined in the mid-20th century, from the Greek hypo, "under," and oxygen.