Hello, I understand your concern. Stomach acid finds it easier to regurgitate through a labile gastro esophageal sphincter when lying down. In the lying position, the acid can stay in the food pipe longer thus causing irritation in the moist inner layer leading to cough and chest tightness. With longer exposure to acid, the inner layer of the food pipe can become insensitive and you don t feel the heartburn, but coughing, chest tightness and even hoarseness of the voice are clear signs of heartburn. I recommend you start by making adjustments to your diet, avoid taking caffeine containing food and drinks, such as coffee, tea, chocolate, as well as any foods that you have noticed to give your heartburn; also spacing the time of your dinner and bedtime up to 2-3 hours would make a significant difference in the quality of your sleep and lessen the heartburn. Drinking plenty of water can also decrease the amount of acid your stomach produces. If these lifestyle changes do not bring you any relief, than taking over the counter anti acids would be the next reasonable step. Wishing you all the best.