Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Swallowing difficulties is nonspecific sign and may indicate several conditions. It is seen in smokers commonly. Also it can be sign of esophageal spasms, tumors or GERD. However, most common cause is hiatal hernia and this means that stomach is protruding through diaphragm muscle. It may cause breathing difficulties,nausea, swallowing difficulties and irritation of stomach. It will also be aggravated by certain food or medications, stress and smoking. You need to avoid fried food, carbonated drinks, coffee, alcohol and spicy food. You should eat more milk products, vegetables and boiled food. Also, certain antiacid medications may be required and as last option, it is possible to perform surgical repair of hernia especially if there are progressive respiratory discomfort and dyspepsia. To diagnose it you should do gastroscopy and if this is negative as in your case then you should do contrast X-rays of stomach. Hope I have answered your query. Let me know if I can assist you further.