I have sudden nosebleed yesterday twice, about 2 minutes or so, not so long, but since it s quite long time already I never have nosebleed, i kind of worried. After consulting local doctor. He advised for x-ray to the paranasal sinus. The result said nothing weird, no sinusitis , only that i have hypertrophy inferior nasal concha. So, my question is, is it related to my nosebleed? Is it allergic reaction? I m working in chemical environment. Is it because of that?