She really is worryingly ill. Just not in the way she believes.
My mother is like this. A hypochondriac who will basically chase a diagnosis and invent symptoms until she can convince a Dr (usually a private Dr) to believe her. She will bang on and on and on about her issues. Some of her issues are absolutely real, but her main and biggest issue is anxiety and healthy anxiety. She needs CBT/anti depressants/anti anxiety medication. But if we suggest that she goes on the offensive and says "well I'm not anxious, I'm just unwell, it's my migraines (insert any other diagnosis she has)". Her health anxiety will just not let her see that it's her anxiety causing these very real symptoms. So it's a vicious circle and nobody can talk her round.
It's exhausting being around her and listening to her obsess in great detail about how she feels. I bet it's the same with Louise. I once told my mother that actually it's was quite unusual for people to feel "well" all the time and that some degree of tiredness, headaches etc was normal. She just scoffed at me and said I didn't understand.
Funnily enough, in the past 6 months my mother has got much better because the "specialist" she sees prescribed her an anxiety medication that is known to help with her other main symptoms. Obviously she's not taking it for anti anxiety reasons.... But it's really helped
who'd have thought it. The specialist knew exactly what he was doing.
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That's not to suggest she (Louise) doesn't have an actual illness. Just that I think her main issue is not what she thinks it is!!