herpes zoster is a viral infection which will affect your nervees and you will have severe pain and fever. It will have to be treated with proper antivirals in severe cases.
Search here and you will find lots of information. Even I did a project on hypertension in pregnancy. I found lots of info here that too in very simple terms. It was good. Try this.
http://www.healthcaremagic.com/healthpage/herpes-zoster