I have a friend who is ill, and it's nothing like I've ever known. Lightheadedness (seems to have getting trouble up and down stairs), constant tiredness, painful to stand after a while and an upset stomach.
Only known foods she can eat without feeling ill (maybe vomiting?) are bran flakes and wine gums. Everything else apparently aggravates.
I'd see a GP. The lightheadedness and tiredness could be lack of food/low blood glucose.
For the upset stomach have you tried flat Coke? It would get some glucose in if you used the classic Coke ie not zero or diet. The mild acidity of Coke seems to help with some upset stomachs and the volume of liquid will help stop dehydration.
HTH
Without more information - I would suggest having the following tested - B12 - FERRITIN - FOLATE - IRON - VITD and a Full Blood count. There is more than one type of anaemia and LOW B12 is VERY prevalent. Also on standing if the blood pressure goes down - it could be Adrenals that are struggling.
b12deficiency.info/signs-an...
Scroll down to look at signs and symptoms and have a good general read of the whole website. You will read things your GP is just not aware of - sadly.
I forgot to mention that her stomach is what hurts when she stands after a while.
...sorry not able to help you with that one as it could be so many things. Did you read the website I posted above ?
I can't see it being that. It came on rapidly, rather than something slow.
NHS Change Day 2014 - less than a week to go!
NHS and bad press
A message from Sir Bruce Keogh on the Urgent and Emergency Care Review
NHS Travel Inoculations. My local G.P demands £30.00 to £40.00 per jab in CASH. Is there any alternative to this extortion?