If you have a heart condition, lung condition, ASTHMA, or if you are experiencing rapid breathing for the first time, go directly to the emergency room.
If you have hyperventilated before due to stress or anxiety, your doctor may have given you information about treating yourself. Lie down, relax, and try to slow your breathing. Try breathing through pursed lips (as if you were whistling), or cover your mouth and one nostril, and breathe through the other nostril. Talk with your doctor about relaxation treatments, to include mindfulness and meditation.