Nosebleed usually starts suddenly and only from one nostril. This can happen quite often. Nasal mucosa can be easily damaged by infection (e.g. common cold) and scabs that often accompany them. However, if the mucous membrane is not hurt, it seems that in most cases the bleeding is coming “for no reason”. In most cases, however, you do not have to worry because the nosebleed is not usually a symptom of another disorder. General blood disease, for example thrombocytopenia may, in rare cases, cause a nosebleed, but with this disease profuse bleeding and in other places usually occurs – for example, from the right or the mouth or under the skin.
Self-help: sit down, lean forward and breathe through your mouth. Close the bottom of the nose to the side of the bleeding by pressing a thumb cheekbone. Press 5 to 10 minutes. This will stop the bleeding. Do not wipe your nose for about 12 hours; then carefully wipe the nose and try not to move the clot that was created and stopped the bleeding.
Professional help: if bleeding persists, consult a doctor or go to the ENT Department (department of ear, nose and throat), to the hospital. Your doctor will probably push a piece of gauze into the nostril and tell you to leave it in the nose for several hours. If the bleeding is persistent or frequent, area of bleeding can be cauterised, and doctor may take a sample of blood to check if you suffer from anemia. It is not likely; generally speaking, despite the outward appearance, with nasal bleeding only a small amount of blood is lost. If your nose is bleeding from quite severe injuries, it is possible that you received deviated septum, which can cause breathing difficulties.
Ask your doctor to check your nose if you are concerned about this possibility.