Hello, I am caregiving for my 88 father in law. He has early stage dementia, which is likely vascular in nature as he suffered a stroke 10 years ago and had to undergo surgery on his brain. He also suffers from peripheral heart disease. For about 48 hours he has been manifesting some signs of a bug, and he had some nausea night before last. I noticed that as he is recovering, he has shown some trembling, severe weakness, instability when he walks and some labored breathing. His stomach is very bloated and he is complaining of lower abdominal pain that comes and goes. There is no fever. Is there a reason to be worried about this?