As others have said it could be a lot of different things, my other half got ill about 12 years ago now, she has had a million test and they still don't know whats wrong with her. Its stomach/bowel related and a gluten free diet has helped her a lot although she is not alergic to wheat or coeliac according to the experts. They think it might be some sort of parasyte or a problem with her stomach acid. She still gets ill from time to time but its not really too serious and only lasts a few hours at a time. In your case it could be a million different things, the human body is very complex, My thoughts are with you both, I hope its not something serious.
Chunky not sure how you and your good lady are but my wife had exactly the same symptoms and after loads of tests it was basically put down to hormones. Basically something that happens as women age changes them far more than us men who probably have any easy life if we'd care to admit it. Fingers crossed you will have the same diagnosis. ps we hard men are all the same. one bit of doubt and we **** ourselves and think the worse whereas the women just plough on. My missus had the old breast lump also a few years ago so i automatically think the worse and again it turns out to be nothing more than womens problems. So when she asked me to get the snip I went straight off and never uttered a word Good luck and I really hope you are worrying about nothing