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 chest pain, sudden shortness of breath, coughing up blood, fainting, or another severe and rapidly developing symptom.
Contact your therapist or healthcare team promptly if you develop increasing swelling, worsening pain, repeated giving way, new catching, or difficulty following the exercise plan.
A knee that becomes locked and cannot straighten needs urgent assessment.
After surgery, seek prompt advice for wound drainage, spreading redness, fever, or pain that is worsening instead of settling.
New one-sided calf pain or swelling requires urgent medical assessment because it can be a sign of a blood clot.
Questions about exercise progression, work restrictions, or expected soreness can usually wait for routine follow-up.
Every sign above is quoted from the sofidex article on Rehabilitation for a meniscus tear. If you are not sure, err upward — it is always reasonable to be checked.