Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Get emergency help for shoulder or arm discomfort with chest pressure, shortness of breath, sweating, nausea, faintness or pain spreading to the jaw or back.
These symptoms may be related to the heart.
A visibly deformed shoulder, an open wound, or loss of circulation or feeling after a major injury also requires emergency care.
Seek urgent medical advice if the shoulder becomes hot, red or markedly swollen, especially with fever or feeling unwell.
Sudden weakness, persistent numbness or inability to move the arm after an injury also needs prompt assessment.
These features are not typical of frozen shoulder.
Arrange a routine appointment if shoulder pain or stiffness lasts more than a few weeks, gradually worsens or makes normal activities difficult.
Seek earlier assessment if you have diabetes, a thyroid condition, a recent injury or recent surgery.
Every sign above is quoted from the sofidex article on Frozen shoulder. If you are not sure, err upward — it is always reasonable to be checked.