Why am I sneezing blood?

Okay first off,never used any drugs that require snorting or shooting,in all honesty,I'm a simple pothead,buut,out of nowhere last night from my first sneeze to my last was nothing but blood,the internet just called me a cokehead and was done with it,but with a drug or blood test you can see the only thing I've don't is smoked a lil pot,anyways,if you have a different answer other than I'm a coke head,let me know I don't like sneezing up mad amounts of blood