The tests needed to evaluate dizziness will depend on the information gathered during the clinical interview. Confirmation of the clinical diagnosis through physical examination and laboratory testing is necessary. In order to document whether there is a fall in blood pressure as the person stands up, examination should include blood pressure measurement in the lying and standing positions. Checking for vestibular abnormalities, examining vision, observing gait, and looking for neurologic abnormalities can be helpful. Important laboratory tests include measures of blood cell counts, thyroid function, blood chemistry (such as sodium), kidney function, calcium, and liver function. Sometimes additional tests may be needed to clarify the diagnosis. These could include tests of hearing and vestibular function, monitoring heart rhythm, evaluation of hearing, or CT or MRI scanning of the head.