Off and on I notice streaks of blood in the mucus in my throat. I have allergies and always have post nasal drip. The mucus is clear, not discolored so I don't think it's an infection. I don't smoke or drink. Can allergies cause blood in your mucus? I don't have the money to go to an ENT and my reg doctor told me he doesn't know. Oh, also, when I notice the blood, I haven't had a bloody nose or picked my nose or anything.
And if definitely seems to be coming from my sinuses or throat because I never cough it up or anything. I see discolored mucus (from the blood, not yellow or green) when I brush my teeth in the back of my throat from time to time.