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 immediately for:
Difficulty breathing or rapidly worsening shortness of breath
Noisy, high-pitched, or laboured breathing
Rapidly increasing swelling beneath the tongue, jaw, or neck
Inability to swallow saliva or severe drooling
Blue, grey, or very pale lips or skin
Confusion, collapse, or difficulty staying awake
Emergency transport is safer than driving because airway swelling can progress during the journey.
Go to an emergency department urgently if you have mouth or lower-jaw swelling together with fever, a raised tongue, a muffled voice, difficulty swallowing, or trouble opening your mouth.
Breathing may still seem normal early in the illness.
And for anyone, someone who:
has chest pain, tightness or pressure lasting more than a few minutes
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
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 the treating service promptly if fever returns, swelling increases, a wound begins draining more, or pain worsens instead of improving.
3
Does any of this apply?
Book an appointment
After hospital treatment, routine follow-up is used to check healing and address the dental source.
The article also says
Do not try to examine or press down the tongue if breathing is difficult.
Do not lie flat if that makes breathing worse.
Every sign above is quoted from the sofidex article on Ludwig angina. If you are not sure, err upward — it is always reasonable to be checked.