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 stroke-like symptoms, loss of consciousness, a seizure, or a sudden severe headache with neurologic changes.
And for anyone, someone who:
Seek urgent medical assessment for sudden hearing loss, new persistent facial weakness, repeated vomiting, or a major new change in walking.
And for anyone, someone who:
Follow-up usually includes MRI, hearing tests, and symptom review.
Timing depends on the management approach, tumor size and growth, and whether any tumor remains.
After surgery, follow-up depends partly on whether removal was complete.
The article also says
People under observation often have closer imaging at first, with longer intervals if scans remain stable.
Long-term monitoring may still be necessary because growth can begin after stability.
After radiation, MRI assesses long-term tumor control.
Temporary swelling can make a treated tumor appear larger, so results must be interpreted over time.
Contact the treating team for gradual hearing changes, worsening tinnitus, increasing imbalance, new facial tingling, or rehabilitation questions.
Every sign above is quoted from the sofidex article on Acoustic neuroma. If you are not sure, err upward — it is always reasonable to be checked.