In addition to some antibiotics for this inflammation, you must use phlegm remedies when coughing with pus runny nose. Because if the pus is not discharged, it can easily lead to a chronic rhinitis and chronic sinusitis. In addition, pus nasal mucus can easily flow back into the pharynx at night, which may be inhaled into the lungs and cause secondary lung infections if you are not careful. Therefore, it is especially important to drain the phlegm and pus as much as possible during the daytime when you are awake. If you have nasal congestion, you can use some medicines to clear the nose.