Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. First of all you need to check your blood pressure and blood sugar periodically. Low blood pressure and low blood sugar can cause sudden dizziness like what you have experienced. Sometimes even diseases of the inner ear like - Labyrinthitis, meniere s disease can cause sudden dizziness. I suggest you to have an ENT consultation once and see if there is any problem in the inner ear. Anxiety, stress, depression, lack of sleep etc an also cause dizziness like that. If you have any such problems consult a psychiatrist and get evaluated. Apart from this heart conditions like abnormal heart rhythms can also cause dizziness. Consult a physician and get an ECG done. If there is any abnormality in the brain that can also cause such conditions. You need to get a neurologists opinion for that. So, I suggest you to undergo a thorough evaluation with all the above specialists i mentioned. Hope I have answered your query. Let me know if I can assist you further.