Colds belong to the upper respiratory tract infections caused by viral and bacterial infections, lesions in the nose when the site of disease rhinitis can appear in the nosebleed. Most of the inflammatory reaction leads to the nasal mucosa edema, brittle, while the capillary expansion, in the external impact or their own injury after the breakage and bleeding. Due to the increase in nasal secretions during a cold, a part of the snot air-drying, will form a dry crust attached to the nasal mucosa, at this time the patient picking the nose will be the nasal mucosa on the dry crust picking off is pulling the fragile mucosa will lead to mucosal breakage and nosebleed occurs. Picking the nose, sneezing and blowing the nose after a cold can easily lead to mechanical damage, which in turn can lead to nosebleeds. Nosebleeds after colds can also be caused by other reasons, please actively seek medical attention after the onset of the disease, after the doctor’s systematic examination to clarify the cause, standardized diagnosis and treatment.