Hi Dear ,
As per your query your sister have episodes od dizziness which start from last year and they are more frequent fron last 2 days along with cold . Well the symptoms you mention in query can occur due to may reasons like
low blood sugar or iron level , due to certain medicines , benign paroxysmal positional vertigo (BPPV) ,
ear infection , meniere's disease . Sometimes infection from upper respiratory track ( in case of cold and
post nasal drip ) can also infect ear through eustachian tube and cause such symptoms . I would suggest you to tale proper rest , avoid ending forward , take steam and apply dry hot compresses to exetrnal ear .
Consult ENT specialist for propee diagnosis . Doctor may order certain test like CT scan ,
blood test , MRI, viral culture test and examination with otoscope . Doctor may prescribe anti emetic drug , anti viral drug ( acyclovir ) , decongestant and ani inflammatory .
Hope your concern has been resolved.
Get Well Soon.
Best Wishes,
Dr. Harry Maheshwari