The redness and bleeding of the nostrils may be caused by allergic rhinitis, acute rhinitis, or damage to the nasal mucosa caused by nose picking. 1. Allergic rhinitis: mainly caused by contact with allergens, which can lead to allergic reactions in the nasal cavity, sometimes causing congestion and swelling of the nasal mucosa, and because the nasal mucosa is relatively fragile, rubbing the nose is likely to lead to bleeding nostrils. 2. Acute rhinitis: mostly seen in viral infections, but also may be secondary to bacterial infections, which can lead to increased permeability of the nasal mucosa, when blowing the nose or rubbing the nose, it is likely to lead to nasal mucosal breakage and bleeding. 3. Digging the nostrils: often digging the nostrils, it is easy to cause the nasal mucosa rupture, causing bleeding, when the secondary infection, it is also easy to lead to red nostrils. If the redness and bleeding of the nostrils continue to be unrelieved, it is recommended to go to the hospital in time to find out the cause for targeted treatment.