This is Dr. David
a synacthen test is also called an ACTH simulation test and is used to test your adrenal glands and pituitary hormones.
During the test, a small amount of synthetic ACTH is injected
Commonly reported reactions are nausea, anxious sweating, dizziness, itchy skin, redness and or swelling of injection site, palpitations
I bet you are having common side effects to the synthetic ACTH injected, which can last for a few days.
these side effects should get better.
when do you go back to your doctor to get your results of your test?