How does it feel when your oxygen is low?

Fatigue: Headache, low energy, lethargy, shortness of breath, heart palpitations, feeling sleepy and tired, pale and having to take rapid, shallow breaths. These are the common symptoms.

Many symptoms: If your oxygen level is very, very low, a person passes out and loses consciousness. But in less severe circumstances, a person might feel dizzy or short of breath. One might experience unusual fatigue - exhaustion with normally easy activity. The heart rate and breathing rate speed up to compensate for the lower level of oxygen. A person might feel "air hunger." get checked if any of this applies.