Definition
A sealed pressure vessel in which a person breathes 100 percent oxygen at pressures greater than normal atmospheric pressure, used to treat decompression sickness and related conditions by forcing nitrogen bubbles in the body to dissolve and be flushed out through normal breathing.
Plain English
A sealed room or tube where a patient is placed under higher-than-normal air pressure while breathing pure oxygen. The extra pressure shrinks the gas bubbles in their body that are causing symptoms, allowing them to be safely absorbed and breathed out.
Context Anchor
Seen in high-altitude physiology, decompression sickness, and emergency medical treatment discussions.
Derivation
From Greek 'hyper' meaning 'over' or 'above', and 'baros' meaning 'weight' or 'pressure'. So 'hyperbaric' literally means 'above normal pressure', which is exactly what the chamber provides.
Why Pilots Care
It is the standard medical treatment for decompression sickness that does not resolve after descent and oxygen breathing.
Grounding Statement
Picture a sealed medical room where the air pressure is carefully increased around the whole person, not just oxygen delivered through a mask.
Intuition Check
A hyperbaric chamber is not just an oxygen tent or a normal medical room. The key feature is increased pressure around the body.
Example Sentence 1
After the pilot reported joint pain and tingling following the unpressurised flight at 22,000 feet, the flight surgeon arranged transport to a hyperbaric chamber for treatment.
Example Sentence 2
Training materials explain that a hyperbaric chamber recompresses the body to relieve joint pain and other effects of altitude DCS.