Thank you for this question. There are many different possible explanations for the bump that you describe, so it is important that you speak with your doctor
. Most often, these sort of problems tend to come from either infection or trauma. Those are the two most common causes of bumps that we all have on the various parts of our body. In most cases, these sorts of these tend to resolve by themselves over time, and we can usually tell that they are harmless because they come on suddenly and go away quite quickly as well. Unfortunately, most of these sorts of problems tend to have some pain associated with them as well, due to the local tissue reactions that are caused by the rapid changes in local volume of blood flow and infection fighting cells. In your case, the fact that you describe a painless bump could be more concerning. For example, some painless bumps can stem from problems such as cancer. The only way to tell what is causing your symptoms is to speak with your doctor about them and get the needed testing to determine what the next step should be. Please do not delay this, and please speak with your doctor about your problem and symptoms.