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 emergency medical help for:
New difficulty starting or controlling urination
Loss of bladder or bowel control
Numbness around the genitals, anus, buttocks, or inner thighs
Rapidly worsening weakness in both legs
Severe back pain after major trauma, especially with weakness or numbness
These symptoms can indicate serious nerve compression or spinal injury.
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 you develop new or increasing leg weakness, worsening numbness, repeated falls, or a clear reduction in how far you can walk.
They need urgent assessment even if spondylolisthesis has not been diagnosed.
3
Does any of this apply?
Book an appointment
Arrange a routine appointment if back pain lasts for several weeks, keeps returning, interferes with sleep or daily activities, or is accompanied by leg pain, tingling, or numbness.
A child or teenager with persistent activity-related back pain should also be assessed.
Every sign above is quoted from the sofidex article on Spondylolisthesis. If you are not sure, err upward — it is always reasonable to be checked.