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If you have headaches and hot flashes and lightheadedness with a feeling of passing out, you could be having either polycystic ovarian disease or GERD with or without H pylori infection. These are the two conditions to be ruled out first. Other conditions to be strongly ruled out in your case could be cervical spinal nerve compression, Meniere’s disease of the ear, wax in the ear, infection of the middle or inner ear, benign positional vertigo and benign intracranial hypertension. Hence it is important to consult an ENT specialist and a neurologist too. At times back and neck problems may persist for years before they really start giving trouble. Chances of TMJ too should be looked into. Other causes are anemia, hypoglycemia or low sugar and some endocrine problems, such as an underactive thyroid (called hypothyroidism), overactive thyroid (called hyperthyroidism), adrenal insufficiency (called Addison's disease), and in some cases, diabetes, may lead to hypotension and hence lightheadedness and an off balance feeling. It can also be an anxiety and panic attack. It is really difficult to comment on the net. I suggest you consult your PCP to run the basic investigations and get an insight into what could be the cause. Depending on clinical examination and tests, your PCP can refer you to the appropriate specialist. Take care!