Coughing up yellow phlegm from a cold is not a good thing. It is often a sign of a combined bacterial infection and an aggravation of the cold, and requires prompt medical attention. Cold is a common acute upper respiratory tract viral infectious diseases, usually patients can appear nasal congestion, sneezing, runny nose, fever, cough, cough and other symptoms, usually about a week of colds can be self-healing. Usually, the respiratory tract produces a lot of secretions and coughs up white mucus sputum when the patient has a cold. If their own immune deficiency or treatment is not timely combined with bacterial infection, the sputum can appear color change, showing yellow, green, etc. In addition, the patient may also appear yellow snot, cough aggravation, sore throat and other symptoms. When the cold patients found coughing up yellow sputum, need to consult a doctor in time, follow the doctor’s instructions for examination, it is best to carry out sputum culture, according to the results of the drug sensitivity test, choose the sensitivity of antibiotics for treatment.