Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services if there is severe confusion, inability to stay awake, collapse, very slow or difficult breathing, or an unusually low body temperature.
Sudden difficulty breathing from neck swelling also needs emergency help.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek prompt medical assessment if:
A thyroid swelling grows quickly or becomes painful
You develop new hoarseness or worsening trouble swallowing
You have persistent racing or irregular heartbeats
You are pregnant, or find out you are pregnant, while taking thyroid medicine
Your symptoms worsen after a medication or dose change
3
Does any of this apply?
Book an appointment
Arrange a routine appointment if you develop ongoing tiredness, cold sensitivity, constipation, menstrual changes, unexplained weight change, or swelling at the front of your neck.
These symptoms are not specific to Hashimoto's thyroiditis, but they may justify thyroid testing.
Every sign above is quoted from the sofidex article on Hashimoto's thyroiditis. If you are not sure, err upward — it is always reasonable to be checked.