Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Get emergency help if hearing loss follows a serious head injury or occurs with signs of a stroke, such as facial weakness, arm weakness, severe loss of balance, confusion, or difficulty speaking.
Seek urgent same-day medical assessment if hearing drops suddenly in one or both ears, especially if the change developed over hours or within a few days.
Do not assume that a suddenly blocked feeling is wax.
Prompt medical advice is also important for hearing loss with severe ear pain, bloody or pus-like discharge, fever with significant illness, a foreign object in the ear, or new weakness or numbness.
Arrange a routine appointment if hearing has gradually worsened, tinnitus is persistent, one ear hears noticeably less than the other, or hearing difficulty is affecting conversations, work, school, or safety.
Children with possible hearing, speech, or language difficulties should be assessed without unnecessary delay.
Every sign above is quoted from the sofidex article on Hearing loss. If you are not sure, err upward — it is always reasonable to be checked.