I have phlegm in my throat and I feel nauseous when I brush my teeth in the morning?

This is usually considered chronic pharyngitis, which can often be triggered by frequent irritating coughs in the morning or with nausea, or by swallowing movements that irritate the pharynx when brushing the teeth. There is usually no sputum coughed up, or only a small amount of granular couscous-like secretions are coughed up.