### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
Since 3 weeks ive been suffering from episodes of sudden dizziness that does not last more than one minute but that is followed by nausea and sometimes palpitations and rapid breath.I have done some blood tests incincluding cbc, ferritin, vitamin b12, TSH, T3and T4. All results were normal. What could be the reason behind such repeated episodes of dizziness? Note: such symptons appear once or twice a week and less when I am relaxed.

### output:

Hi, Thanks for writing in. Dizziness can also occur due to stress related anxiety or overflow of emotions. However, before saying that your symptoms are due to anxiety, the following other causes of dizziness and nausea must be evaluated. Short duration of dizziness can also 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. You might require a CT scan or MRI scan of the brain. 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. Clinical examination of inner ear and vestibular system in the ear is also required. For this you might have to consult the ENT specialist. After clinical examination if there is suspicion of inner ear problems then detailed investigation is required. It might help to do an Electronystagmography (ENG) or videonystagmography (VNG) done to record abnormal eye movements while the head is placed in different positions or your balance organs are stimulated with water or air.