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 trouble breathing, swelling of the face or throat, fainting, or another severe reaction after using a hair-loss product or medicine.
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 for:
Sudden or rapidly increasing hair loss
Smooth bald patches or loss of eyebrows and eyelashes
Scalp pain, burning, redness, heavy scale, crusting, or pus
A shiny area where follicle openings are disappearing
Hair loss with fatigue, unexplained weight change, menstrual changes, or other new symptoms
Hair loss in a child
Shedding that begins after starting or changing a medicine
3
Does any of this apply?
Book an appointment
Routine follow-up is useful after starting treatment because changes in hair growth are slow.
Clinicians may compare standardized photographs, check for side effects, and decide whether the plan remains worthwhile.
It often takes several months to judge a treatment fairly.
Arrange a routine medical appointment if hair loss is persistent, gradually worsening, emotionally distressing, or difficult to explain.
The article also says
Baldness is rarely an emergency.
Every sign above is quoted from the sofidex article on Baldness. If you are not sure, err upward — it is always reasonable to be checked.