Sweat abnormalities are commonly found as sudomotor dysfunction as part and parcel of having Autonomic Neuropathy, something which can be autoimmune or Diabetes related or just idiopathic.
QSART and TST are the two Autonomic Function Tests used to check for this.
Quantitative sudomotor axon reflex test (QSART) is used to evaluate postganglionic sympathetic cholinergic sudomotor function by measuring the axon-reflex mediated sweat response over time
Thermoregulatory sweat testing (TST) is used to evaluate the integrity of central and peripheral sympathetic sudomotor pathways from the CNS to the cutaneous sweat glands. The core body temperature is raised by increasing the ambient room temperature which in turn raises blood and skin temperature. The degree and extent of sweat production is then visualized with an indicator dye.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3046462/
Sudomotor dysfunction often occurs along with having cardiac output issues (POTS, OH etc) too. A full Autonomic Function Test panel work-up checking out the cardiac side of things would also include doing a Tilt Table Test, Valsalva Manouvre and Heart Rate Variability to Deep Breathing Tests.