Why when i throw up lately sometimes my nose starts to bleed really bad?

Nosebleed: When you throw up some of the stomach acid gets into your nostrils and burns it, so it causes you to bleed.

Increased Pressure: Increased vascular pressure associated with throwing up can cause nose bleeds and esophageal bleeds, which then leak stomach acidic fluid into the chest cavity and can cause sudden heart attack. I suspect you might be fighting bulimia. With bulimia, you can appear 'fine' and die anyway, due to the aforementioned cause. Seek help! (oa, cbt & meds for eating disorders!)).