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
Seek emergency care for severe difficulty breathing, crushing or persistent chest pain, fainting, or signs of a serious allergic reaction.
These are not expected routine effects and need immediate assessment.
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
Contact your radiation team promptly if you develop:
Blistering, moist peeling or an open area of treated skin
Rapidly increasing redness, warmth, swelling or pain
Fever or drainage that could suggest infection
New or increasing arm, hand or breast swelling
A persistent new cough or shortness of breath after treatment
Pain that is not controlled by the plan your team provided
Contact the team sooner if you are unsure or symptoms are interfering with sleep, eating or daily activity.
The article also says
Mild tiredness, gradual skin darkening and manageable tenderness can usually be discussed at your next scheduled treatment review.
Every sign above is quoted from the sofidex article on Whole breast radiation therapy. If you are not sure, err upward — it is always reasonable to be checked.