His doctor might be right. Dehydration
does cause dizziness
and headaches. Let him continue to drink plenty of water and eat healthy.
In the meantime it would be worthwhile to get a couple of blood investigations done, like, Hemoglobin
, Thyroid function test, Vitamin B12
levels, blood sugar levels, serum electrolytes . Sometimes, abnormalities in the above mentioned tests could cause symptoms similiar to what he is experiencing right now.
Dizziness and headaches could also be due to stress or anxiety. I would also advise him to sign up for yoga/ relaxation classes.
Hope this helps.
Dr. Divya Kuttikrishnan