Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek emergency care for bleeding that is heavy or does not stop with firm, continuous pressure, or for signs of a severe allergic reaction after using a treatment, such as trouble breathing or swelling of the face or throat.
Seek prompt medical care if the surrounding skin becomes increasingly red, hot, swollen, or painful, or if pus or fever develops.
These can be signs of a bacterial infection.
Arrange a routine appointment if you are unsure whether a growth is a wart, especially if it is new or changing.
You should also seek routine medical advice if it is painful, repeatedly bleeds, spreads widely, returns often, or does not improve after correctly used nonprescription treatment.
The article also says
Get advice before treating a suspected wart yourself if it is on the face or genitals, or if you have diabetes, poor circulation, reduced sensation, or a weakened immune system.
A clinician should assess genital growths because other conditions can look similar and treatment options differ.
Warts are not normally an emergency.
Every sign above is quoted from the sofidex article on Warts. If you are not sure, err upward — it is always reasonable to be checked.