My nose is bleeding uncontrollably in the mornings and evewhen im sleeping when im on my back i can feel it flowing down in my throat i can't smell as well what can it be?

Doctor can evaluate: Nosebleeds can be due to many things that cause one of the little veins on the inside of the nose (usually the middle septum) to crack and leak temporarily. Heavy breathing in sports, hot or cold air, allergies, nose-picking, colds, a toy in the nose, etc., are some of the causes of nosebleeds. He who bleeds too often or too long can have his blood checked to see if his blood clots too slowly.