what causes blood noses

Blood noses, or nosebleeds, are primarily caused by irritation or damage to the tiny blood vessels inside the nose, which lie close to the surface and are easily affected. The two most common causes are dry air, which dries out the nasal membranes making them more susceptible to bleeding, and nose picking. Other causes include acute sinusitis, allergies, injury or trauma to the nose, use of blood thinners or aspirin, chemical irritants, infections like colds, nasal sprays, a deviated septum, and habitual nose blowing. Less commonly, underlying conditions like bleeding disorders, nasal tumors, or hereditary problems can also cause nosebleeds. Nosebleeds often occur more in winter due to dry indoor air and cold viruses. Though they can be alarming, most nosebleeds are not a symptom of high blood pressure and are usually manageable.