Hi, I am 20 years old and I have a lump right behind my right jaw under my ear that I'm wondering about. It's hard and immobile. It's hard to say how big it is, but it seems like it's about the size of my fingertip. There's no lump like that on the other side. I'm not sure how long it's been there, but I noticed it over a month ago when I started feeling random sharp pains there every now and then that would last about a second, and when I felt for the source of the pain I discovered the lump. The pains only lasted a day and I haven't felt any pain there since. It's not tender at all and doesn't hurt. In fact, compared to the other side, the other side feels much more tender when I press it. It just feels like a bone. It seems-but I can't be certain-that the size of the lump changes and sometimes it's bigger and sometimes smaller... I haven't been checking on it on a regular basis though. I have scoliosis and was thinking that it might just be something that sticks out further on one side of my neck because of that, so I decided to just wait and see. I get frequent colds. I also have a piercing that's been somewhat infected and not really healed completely for about half a year or so. I'm not sure if it's a swollen lymph gland or what. I don't have any insurance so I wanted to see if this was something I should worry about before going to the doctor. So I wanted to know, what should I do about this-is it something I should get checked out, wait and see, or what? What are the possibilities this could be?
Without an examination, is it not possible to tell you exactly what this could be. However, that said...
You state that the lump is hard, bone like, not mobile, and located just behind your jaw, under the ear. In that location, there is the mastoid process. This is a bone, part of the skull (the temporal bone actually), which projects down and forward, just behind the ear. Several muscles attach to the mastoid process, thus one can actually develop an osteophyte there (a bone spur).
So, it is possible to have one mastoid process larger than the other side. Though it is not common.
If the attachments of the muscles around the osteophyte becomes inflamed, it could become swollen and tender.
Of course there are other causes of lumps and bumps in the neck region. Enlarged lymph nodes are the most common, but these are usually mobile, and tend to be along the side of the neck, within the anterior or posterior cervical lymph node chains.
Skin cysts such a sebaceous or epidermal cysts are also common in the neck region. But, again, these are usually mobile and tend to be swollen, warm, red, and tender.
Since you are not having any problems with it at present, you can probably just watch it and wait and see if any symptoms develop. If you develop tenderness over the lump, or it becomes more swollen, red or warm, then you may have to see someone about it.