Yes for at least two reasons. Firstly, holding your breath can cause you to pass out. Secondly, holding your breath while the pressure is decreasing can cause a

Yes for at least two reasons. Firstly, holding your breath can cause you to pass out. Secondly, holding your breath while the pressure is decreasing can cause an embolism (air can enter a blood vessel in the lung) which can form a clot and kill you: http://en.wikipedia.org/wiki/Air_embolism#Gas_embolism_in_diving http://en.wikipedia.org/wiki/Air_embolism#Gas_embolism_in_di...