My wife is having headache, sweating unnecessary, dizziness such that she can't stand too long. a doc told she had enemia and that she might need blood transfusions. which specialist can i go for? or how can we bring her health to normal?

Need to see a doctor: While she may be anemic, which can be handled by any primary doctor or hematologist, her symptoms are concerning for possibly a more serious disorder causing her blood pressure to be elevated, which may be causing her symptoms. I would imagine any physician in this case would want to check thyroid studies, and maybe urine catecholamines.