<s>[INST] a certain feeling comes in/on my leg/thigh and I know I m going to faint. I do not feel it in my head, but my leg/thigh only 1. then I need to lay down and wait for it to pass, that s when I know it s in my head also, the fainting.. but I feel it in my leg/thigh. only one. If I am standing I must immediately sit/lay down or I will fall/pass out. Usually I make it to the bed/sofa/chair. that s when I notice the blacking out would be in my head. [/INST] Hi, Thanks for writing in. Moments of dizziness can happen due to decreased blood flow from heart to brain. When it happens, the blood flowing through the vessels from heart to brain might have a reduced flow. These are by the carotid and vertebral arteries on either sides. This is more significant when you are standing upright and doing any moderate to heavy physical activity. Since he has got scans for inner ear and brain done, it is confirmed that there is no abnormality in the vestibular system in the ear or any serious conditions in the brain. After clinical examination, your doctors might recommend CT scan or MRI scan brain to know any problems within the brain and Electronystagmography (ENG) or videonystagmography (VNG) to record abnormal eye movements while the head is placed in different positions or your balance organs are stimulated with water or air. For this he might consult the ENT specialist. The best way to analyze if the reduced blood flow to the brain is causing your dizziness is by doing a carotid and vertebral arteries Doppler ultrasound. It will show the flow of blood from the heart to the brain and if it is adequate. Dizziness can also occur due to stress related anxiety or overflow of emotions. </s>