Really, the only way to be sure is to see a doctor. When I notice a symptom, I go through a regular thought process.
1. Have I had this symptom before? If not, and it's something that might be of concern, then I see a doctor.
2. If I have, then is it more intense that it was before? If yes, I'll again see somebody about it.
3. Is it debilitating, or restricting my ability to go about life like normal. If yes, then I see somebody.
4. Does it persist for multiple days. Again, a yes will ensure that I seek support.
5. Accept it's probably anxiety, go about life, and not worry too much.
I always take a 'better safe than sorry' approach. Certain things, such as chest pain, are always, in my opinion, worth getting checked up on.