A 3-year-old child’s recent sleep cough may be caused by physiological factors, but can also be caused by pathological factors such as bronchitis and pollen allergies. 1. Physiological factors: children sleeping on their sides, lying on their stomachs, or sleeping on too high a pillow, may lead to the child’s lungs and bronchi and other organs to breathe poorly, thus causing a cough. Or the air in the bedroom is not circulating, will lead to turbid gas into the child’s respiratory tract and produce irritation and cause cough symptoms. 2. Pathological factors: when the body’s bronchial tubes are attacked by bacteria, fungi and other pathogenic microorganisms, it will lead to bronchial mucosa edema, hyperplasia and other inflammation, which will cause the symptoms of children’s cough. If you are allergic to pollen, accidental contact with allergens can irritate the mucous membrane of the respiratory tract, thus causing cough symptoms. 3-year-old child recently sleep cough, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.