Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Call emergency services for sudden facial drooping, arm or leg weakness, severe loss of balance, difficulty speaking, or a sudden severe headache.
These can be signs of a stroke or another emergency rather than cervical dystonia.
A new abnormal neck position after a significant injury, especially with weakness, numbness, severe pain, or loss of bladder or bowel control, also needs emergency assessment.
Contact your treatment team promptly if symptoms change significantly, injections provide much less benefit than expected, or you develop troublesome neck weakness or swallowing difficulty after treatment.
Seek urgent medical help if you cannot swallow fluids, are repeatedly choking, or develop breathing difficulty, particularly after botulinum toxin treatment.
Arrange a routine medical appointment if you develop repeated or persistent neck pulling, involuntary head turning, or an unexplained head tremor.
Gradual symptoms still deserve assessment, especially when they cause pain or interfere with daily activities.
Every sign above is quoted from the sofidex article on Spasmodic torticollis. If you are not sure, err upward — it is always reasonable to be checked.