Hello! After a careful assessment of your discussion, I want to suggest you the following
1) The symptoms described by your father may be attributable to two major causes
2) The first being possibility of IHD ( Ischemic heart disease
), for which he needs to have consultation with an eminent cardiologist & investigated further like ECG & treated accordingly.
3) The second possibility is of having diabetes
, for which he should have a consultation with a diabetologist
& investigated, particularly blood glucose
levels & HbC1. The symptoms may be caused by diabetic autonomous neuropathy.
Thanks & wishing a speedy recovery for your father!