Nosebleeds in both nostrils at the same time may be caused by physiological reasons such as dry weather, or allergic rhinitis and blood clotting disorders. 1. Dry weather: When the weather is dry, the child’s intake of water is insufficient, which may also lead to rupture of the nasal mucous membrane, resulting in the symptom of nosebleed from both nostrils at the same time. 2. Allergic rhinitis: Allergic rhinitis can irritate the nasal mucosa, leading to vasodilatation, so the child will have two nostrils at the same time the phenomenon of nosebleeds. 3. Coagulation dysfunction: Coagulation dysfunction is caused by certain genetic factors or external factors, resulting in the lack of coagulation factors, the child will have two nostrils at the same time the symptoms of nosebleeds, and some patients will also be accompanied by hematuria and blood in the stool. When your child has nosebleeds from both nostrils at the same time, go to the hospital and get a clear diagnosis of the cause of the problem and treatment under the guidance of the doctor.