What can cause post-nasal drip with blood? i think i have an infection or allergy or sinusitis- green mucus and post nasal drip with clogged up nose and recent cough. in fact, since i can remember i have had a stuffy nose with plenty of mucus in my nose.

Acute : Acute sinusitis is characterized by increase mucous (often colored), sinus pain/pressure, nasal congestion/clogging), cough, nose bleeds (epistaxis), minimal if any fever. It most often goea away on its own but antibioticas can help if the symptoms persist longer than 10-14 days without improvment. Nose bleeds this time of year are very common as the air in our homes is very dry due to our heating systems. It would be important to moisten the nose with saline sprays multiple (3-4) times a day. That will moisten the lining to help healing and loosen the secretions for easier clearing. I would recomment finding a primary care doctor to help sort out some of your health issues and help avoid the inconvenience and expense of the er for these nonemercencies.

Without : Without getting a full history and examination, it sounds like you probably have acute sinusitis. Although the finding of blood can be quite alarming, it most likely is due to a dry nasal mucosa with a ruptured blood vessel. If your symptoms do not improve or if the bleeding persists, i would recommend evaluation by an ENT physician for a thorough evaluation and proper diagnosis.