Thanks for choosing HCM forum.
You might be having the sebaceous cyst
behind your ears. Try to recollect any infections, treatments, any incidents/happenings, or change in lifestyle in the recent past. Sometimes you may end up finding the cause for this recent aggravation.
Though it does not pose any risk to life, consider getting a doctors visit. Excision or heat pads for more than 10 days are the traditional way of dealing this condition in modern medicine.
offers a huge chance of recovery without an excision. You can consult an expert near you for details.