Is it normal to have more fat/muscle under one arm?

NLK1515

So for maybe a few months now I've started noticing that the armpit of one of my arms has, what I think is more muscle than my other arm (it kind of feels like that when I flex upwards). It's not a small, defined lump or anything, it just feels like a big bump over that area, starting from my upper arm, and descending down over most of my under arm.Like I said, I always just though it was the muscle and...I honestly don't know how long I might have had this for, because I never really paid attention to it, and then I initially completely brushed it off because I thought it was normal until I realised I didn't have that under my other arm, and it started to make me feel really worried.

My other arm just feels a lot smoother, I can feel the muscle under my arm when I press down, but there's no bulge or anything. It wasn't worrying me too much and then for about a week now I started experiencing some pain under my arm with the bump (my right arm). At first I kind of brushed it off as a pulled muscle, and I'm still kind of thinking it is that because when I pulled my hip muscle a few months back it was a very similar feeling. But then yesterday I started thinking that it's on my right arm, and I started overthinking things and...yeah, I don't really know. Obviously I know that body's aren't completely symmetrical, so it could be possible to have more fat/muscle on one side than the other, but is this a normal thing? Does anyone else have this?

MelissaDallas

If I were worried about anything I would start with my primary care doctor.

Moderators

Dear NLK1515,

We second what MelissaDallas suggests. Any change to your breast health or otherwise that causes concern is best to bring up with your primary provider.

The Mods

xxyzed

Me thinking that the muscles under arm one felt bigger than the other is why I went to the doctor. I was referred for an ultrasound and mammogram and went on to be diagnosed with breast cancer. So yes, it can be a symptom. It can also be nothing. Best to go and get checked to be sure