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 possible diabetic ketoacidosis, including:
Severe low blood glucose is also an emergency if the person has a seizure, becomes unconscious, cannot swallow safely, or does not recover after the prescribed emergency treatment.
Contact the care team promptly about persistent glucose readings outside the agreed range, repeated low glucose episodes, new thirst or urination, unexplained weight loss, vomiting, worsening skin problems, changes in vision, or concerns about growth and puberty.
Seek urgent medical advice during an infection or other illness if glucose remains high, ketones are present, or the person cannot keep fluids down.
Follow the individual sick-day plan if one has been provided.
Keep routine appointments with the endocrinology and diabetes teams, even when the person feels well.
Insulin resistance and organ complications can worsen without causing early symptoms.
Every sign above is quoted from the sofidex article on Rabson-mendenhall syndrome. If you are not sure, err upward — it is always reasonable to be checked.