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 severe breathing difficulty, fainting, chest pressure, stroke symptoms, vomiting blood, coughing up blood, or heavy bleeding that will not stop.
A serious head injury while taking an anticoagulant also warrants urgent assessment, even if symptoms initially seem mild.
Follow-up is needed even when symptoms improve.
The rhythm can return without being felt, and stroke-prevention decisions are not based only on whether a person currently notices an irregular heartbeat.
At routine visits, the care team may review:
The article also says
After cardioversion or ablation, follow the specific plan for medicines and rhythm monitoring.
Do not stop anticoagulation or other heart medicines solely because a home monitor reports a normal rhythm.
Seek timely medical advice for increasing palpitations, worsening exercise tolerance, new swelling, repeated dizziness, or possible medicine side effects.
Unusual bleeding while taking an anticoagulant also needs medical review.
Every sign above is quoted from the sofidex article on Atrial fibrillation and atrial flutter. If you are not sure, err upward — it is always reasonable to be checked.