Whether it is an adult or a child coughing, sputum is usually present because coughing is a reaction to an upper respiratory tract infection that irritates the throat, and sputum is caused by increased secretions from the respiratory tract. If the sputum is yellow, it is caused by Staphylococcus aureus infection. If the sputum is pink, it may be caused by a disease such as heart failure, so the original cause of heart failure needs to be treated. If the cough is caused by a bacterial infection, antibiotics, such as cephalosporin or penicillin, are recommended for treatment.