Most patients, who think they have a chest infection have in fact a cold or cough. Good signs of a chest infection are severe fatigue with a productive cough with green sputum AND prolonged fevers AND / OR significant shortness of breath. See also under “coughs”.
See your GP if you believe you have a chest infection or if things are not improving after 7-10 days. Call 111 only when you are seriously unwell and 999 when you think you or another person may be life threateningly unwell.