<prompt> GERD is defined as pH of oesophagus ___ and for ___ of total day time.4 and 55 and 44 and 105 and 10  <response>: pH of esophagus 4 for 5 of total day time is defined as GERD There is Demeester score for the severity of GERD GERD can be due to Hiatus Hernia Incompetent LES Coffee, tea, stress GERD causes - Chemical laryngitis, chemical tracheitis - Nocturnal cough -Asthma -Dental erosions 