What Causes Recurring Dizziness And Vomiting?

My daughter 14 yr having menses since 6months have started complaining of Giddiness since almost six months. Thought it could have been because of hormonal changes initially. But it has become too frequent now. It occurs mostly in morning while she is in school. Once it happened at midnight soon after she slept..that time she vomitted after a while ..became tense with tachypnoea,tingling and extreem weakness. But soonafter vomit she became alright. She dosenot have headache, visual complaint. She,on consultation, dose report relative deafness on rt ear but no discharge. She had adenoids and recurrent bed coryza for years.she use to sleep with open mouth and breathing thru oral cavity more often then nasal breathing.