Hello There are two different symptoms. Pain in the stomach and nausea are related to each other , as these symptoms are for several days and may be due to hyper acidity or gastritis or hiatus hernia ( one and same thing ) , diagnosis can be confirmed by upper G I endoscopy . When such symptoms present , please avoid spicy , greasy , fried foods , don t eat pizza , burger , sweets . Try raising the head of the bed of your husband about 4 inches with blocks. It might also help to avoid eating or drinking for 2-3 hours before he lie down. Also take some antacid but if there is sever pain and nausea , he may need drugs like pantaprazole -d once or twice in day for 10-15 days. He is also having phlegm with cough , if he is a smoker , this is common . If he is not smoker then get in X ray chest because his phlegm was brown color . In my opinion consult a physician because your husband is also feeling weakness beside other symptoms. Good luck.