Later there was the following expression “ She has feeling very unwell and yesterday she developed a rash on her arms, the palms of her hands and the soles of her feet. She also got a very sore mouth.”
If the expression “not feel oneself” has a meaning “you feel slightly ill” as in:
Yes.I don't feel myself=I feel something is wrong with me, perhaps I am ill.
I haven’t been feeling myself since I stopped taking the medicine”
And we can understand that as “ indisposed”, “unwell”, “poorly”, “seedy”. “out of sorts”, “be ailing”, “not feel quite well”, “not feel up to the mark “ then what is the meaning of the expression “She has feeling very unwell”.
I can not see any trick here. Simply, she was really ill. You feel unwell if you have a cold, and you feel very unwell if you get flu.
The second question is regarding to the word “heartburn”. Why there is the root “heart” and the meaning of the whole word “acid dyspepsia” does not concern the heart but the gastro-intestinal tract?
This is a good point. The pain is felt in the cheest
so perhaps this is why.
Thank you in advance for your efforts.
Regards.
V.