How do they test for autonomic dysfunction? what doctor?

Several ways: Ways to test for dysautonomia include a thermoregulatory sweat test, tilt table testing, gastric emptying testing, urodynamics, quantitative sudomotor axon reflex testing (qsart), and labs looking for autoantibodies such as autonomic ganglionic acetylcholine receptor antibody (ab), ganglionic receptor ab, ganglioside ab, antibodies to presynaptic channels, and antineuronal ab. A neuro doc can help.