# Why does a stuffed up nose clear up momentarily when the person having it is startled or has an orgasm?

I have experienced this phenomena many, many times and I'm sure it's not only me. I guess the sudden rise in arousal opens up the nostrils in a kind of fight or flight response, but I'm interested in the more intricate details of why this happens.

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@Speldosa See vasoconstriction:Two common stimuli for eliciting smooth muscle contraction is circulating epinephrine and activation of the sympathetic nervous system (through release of norepinephrine) that directly innervates the muscle. This occurs on the smaller arterioles just before the capillaries. –  Chuck Sherrington Jun 21 '12 at 23:15