I have warm flashes sometimes with no specific body part or time and last a couple of seconds. And if I lie down on my back for an hour or so, the buttocks become numb. If I sit for more than an hour, my legs become numb. Doctors have said there is nothing wrong and have given me nervigen or something similar. But, still the problem continues. What are the tests that needs to be done for diagnosis? Please let me know. Thank you!