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
Get urgent or emergency help if you develop:
New leg weakness or an inability to walk normally
Loss of bladder or bowel control
Numbness around the genitals, buttocks, or inner thighs
Sudden weakness or numbness affecting one whole side of the body
Severe symptoms after a major injury
These signs are not typical of meralgia paresthetica and may indicate a spinal, brain, or traumatic nerve problem that needs rapid 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
Seek prompt medical advice if the pain is rapidly worsening, wakes you repeatedly, spreads outside the usual outer-thigh area, or is accompanied by fever, a rash, swelling, unexplained weight loss, or a new lump near the abdomen or groin.
3
Does any of this apply?
Book an appointment
Arrange a routine medical appointment if numbness, tingling, or burning on the outer thigh lasts more than a short time, keeps returning, or interferes with daily life.
Assessment is also sensible if you have diabetes, recently had surgery, or cannot identify a clear pressure-related trigger.
The article also says
Meralgia paresthetica is not normally an emergency.
Every sign above is quoted from the sofidex article on Meralgia paresthetica. If you are not sure, err upward — it is always reasonable to be checked.