Why Would My 74 Year Old Mother Have Fatigue For

why would my 74 year old mother have fatigue for a few weeks now, followed by her arms burning intermittently on AC area on both arms. Increased saliva and mucus. Today she has wheezing, dry heaving to try and and expelled the much. Voice is different. Stating this morning that she was having increased mucus build up in her throat and having to get it out by dry heaving and pushing it out with her tongue