Q: I recently had a fainting spell, where I fell and hit the back of my head between the ears. I consulted a doctor, but he was not sure what had caused it. They thought that it could be due to dehydration. Its been 4 weeks now, and every night when I lie down, I get a spinning sensation. This also happens when I wake up in the morning, unless I take my time and slowly get up. My doctor told me that it takes time to recover, but the spinning doesn't seem to get better. Do I need have a MRI scan done to make sure that I don't have a tumour. Once I am up in the morning, I feel fine and have no headache or vision issues.

A:The first thing I would do is ask the doctor to check your blood pressure when you are sitting and standing. The symptom you describe is consistent with a condition known as postural hypotension, where a drop in blood pressure occurs when you sit or stand up too quickly. It can occur with dehydration, and also with certain diseases and as the side-effect of some medications. If you do indeed have postural hypotension, then your doctor will have to determine the cause and address it appropriately. If it is deemed that you do not have postural hypotension, and you are continuing to experience the symptom you have described, the next step would be to see a Neurologist (unless the doctor you are currently seeing can come up with an explanation).