@bevsfn I’m sorry to hear that you weren’t given better attention! This disease really needs a full work up because it could be associated with other medical conditions, including autoimmune diseases.
The sweat test is a measurement of your body’s sweat response to an electric stimulation. It’s not painful. Since the sweat response is an autonomic function I think that’s why they use it to diagnose autonomic neuropathy. There are medications they can give you to stabilize your blood pressure if you’re having lightheadedness and that’s found to be the cause. I hope they give you more time at your next appointment! Wishing you the best!