Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for collapse, loss of consciousness, seizures, severe confusion, signs of shock, or suspected adrenal crisis.
Signs of adrenal crisis may include profound weakness, vomiting, severe abdominal pain, low blood pressure, or fainting, especially in someone with known adrenal or pituitary hormone deficiency.
New headaches, vomiting, or vision changes need prompt assessment, especially with a known tumor.
Seek urgent medical care for:
Arrange a routine medical appointment if you develop persistent unexplained changes in thirst, urination, weight, appetite, periods, sexual function, sleep, or temperature tolerance.
Follow-up is also appropriate for ongoing fatigue, slow growth in a child, or symptoms that begin after a brain injury or treatment near the pituitary.
The article also says
If you already have hypothalamic or pituitary dysfunction, contact your care team when symptoms change or prescribed treatment no longer seems to control them.
Every sign above is quoted from the sofidex article on Hypothalamic dysfunction. If you are not sure, err upward — it is always reasonable to be checked.