Note that hypopituitarism will occur in up to 30% of people who sustain a moderate or severe traumatic brain injury (TBI), and can sometimes occur even in mild TBI cases. Hypopituitarism can have symptoms very close to those of ME/CFS.1 Thus there is a real danger of misdiagnosing such symptoms ME/CFS when the true cause is hypopituitarism.
If a traumatic brain injury is involved, and ME/CFS-like symptoms ensue, testing for hypopituitarism would be advisable. The short synacthen test (also called the ACTH stimulation test) is a standard test for hypopituitarism, but this test is not very accurate, and in fact misses 40% of hypopituitarism cases. A more accurate but more complex and risky test for hypopituitarism is the insulin tolerance test.