Nitrox refers to any gas mixture composed (excluding trace gases) of nitrogen and oxygen; this includes normal air which is approximately 78% nitrogen and 21% oxygen, with around 1% inert gases, primarily argon. However, in SCUBA diving, nitrox is normally differentiated and handled differently from air. There has, however, been some suggestion that post dive fatigue is due to sub-clinical decompression sickness (DCS) (for example micro bubbles in the blood insufficient to cause symptoms of DCS)… (More on Nitrox)