Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Sudden onset of giddiness may be due to BPPV or acute labyrinthitis or vestibular neurinitis or transient ischemic attack or hypotension or hypoglycemia etc. Until examination is done it is difficult to say what it is. Avoid spicy food and alcohol avoid smoking and caffeine drinks. Check your blood pressure, hemoglobin status, check for cardiac functioning, MRI brain, tilt table examination etc. Avoid high risk activities. Use tablet Diligan. If symptoms not improved please consult your neurophysician he will examine and treat you accordingly. Take care.