Hi.
My girlfriend is 18 years old. She is still virgin. She recently(from near 4 months) started having a weird problem. Every night she suddenly wakes up ( I asked her,she doesn't wake up dreaming anythng) and become/discouer herself so aroused.. So much aroused that she canly hardly control and it stops when she sleeps again.at morning she discovers pain in whole body. . Its happening every night. Is this normal or she should be concernd? Is this symptom of any deases ?

Sounds like sexual dreams. She either just not admitting dreams to you, or not remember the dreams. We all dream, but most seldom remember the dreams.

At 18, sexual dreams and fantasy is common.

May be. But doesn't it sound weird to having sexual dream continuesly every night since 4 months ? I also dreamt sexual dreams but at best twice or thrice a week. .

Having sexual dreams does not mean she has a disease. Tell her to relax, this is not at all uncommon.