Hello sir, Welcome to HCM. Ok, first af all, please understand that being physically strong doesn t mean at all that one is also physiologically strong and completely immune to every disease. Having said that, you present with a clear history of three distinct pathologies, which can be inter-related. 1. Incase you have water-brash (increased salivation), and acidic eruccation as part of your acidity, then you have GERD (Gastro-Esophageal Reflux Disease), which in 80% can lead to Asthma, and vice-versa. 2. Worsening of your respiratory symptoms in cold and high-altitude (hilly) regions is indicative of Asthma, where there is a development of a few anatomical anomalies of the upper respiratory tract, leading to an Interstitial Lung Disease, which can inturn lead to a decrease in arterial oxygen tention and PND (Paroxysmal Nocturnal Dyspnoea). 3. Mild to severe Respiratory dystress on lying down, which is relieved upon getting up (such as yours) is known a symptom known as PND (Paroxysmal Nocturnal Dyspnoea), which is an indication of Congestive Heart Failure, which can also be brought about by an Interstitial Lung Disease, & th symptoms for which can very easily be confused with GERD. Now, since antacids have had no effect for 4 months, then clearly the root cause for your distress does not seem to be your acidity alone. You may need to undergo cardiac and respiratory function tests as well (like ECG, ECHO, Respirometry e.t.c) to find out the actual cause/causes. Please consult your treating doctor for the same, and for further advice. in the meantime, please refrain from alcohols, smoking, and all fried foods. Wish you all the best, and hope for a speedy recovery