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 for difficulty breathing, severe noisy breathing, blue or grey lips, inability to swallow saliva, sudden severe swelling around the mouth or neck, or marked sleepiness with breathing problems.
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 for:
New pain, tenderness, redness, or warmth
A rapid increase in swelling without breathing difficulty
Fever or discharge from the swelling
New difficulty swallowing or reduced feeding
Increased swelling after an injury
During pregnancy, contact the maternity team promptly if a scan has shown hygroma colli and new symptoms such as bleeding, contractions, fluid leakage, or reduced fetal movement occur.
These symptoms are not specific to hygroma colli but need pregnancy assessment.
3
Does any of this apply?
Book an appointment
Arrange a routine medical review if a known or suspected neck swelling is slowly growing, repeatedly becomes inflamed, or begins to affect eating, speech, sleep, movement, or daily activities.
Every sign above is quoted from the sofidex article on Hygroma colli. If you are not sure, err upward — it is always reasonable to be checked.