The baby has phlegm in his throat. First, increase the indoor humidity. When the air is dry, sputum is not easy to cough up, so it is better to breed bacteria, and then increase and maintain a moderate humidity and temperature, which is conducive to the discharge of sputum from the baby's lungs. Mom and Dad can use humidifiers or mopping methods to increase indoor humidity, and pay attention to regular window ventilation. The indoor air is fresh, and the baby can breathe naturally and smoothly. 2、 Drink water and expel phlegm. When suffering from lower respiratory tract infection, the body will lose a lot of water due to fever, sweating and increased respiratory frequency. Therefore, it is necessary to replenish water for the baby. It is best to keep the baby cool at about 23 degrees. Timely replenishing water can promote fever, improve blood circulation, help to replenish the consumption of respiratory tract and reduce the viscosity of sputum. 3、 Pat your back to dispel phlegm. The baby can't cough out phlegm smoothly. Parents can pat the baby's back in order to help the baby to expel phlegm. The specific operation is to let the baby lie on his side or hold it on his side, with five fingers together, and hold it in an empty fist shape. Gently pat the baby's back, from top to bottom, from outside to inside, and through proper vibration to promote the discharge of sputum, at least five minutes each time, more than three times a day, This is an exact and effective method.