I am 21/female. I have an extremely strong pulse on the left side of my abdomen. It is super strong when lying down, if you put an object on it it would move quite a bit. I have not noticed a visible mass but my stomach on both sides always looks quite distended, even when I have been very thin. I have noticed this for years now, and 3 years ago my Dr. noticed it, but she did not order any tests and said it was just because I was thin enough(5'9, 130 lbs). Since then I've gained about 20 pounds, and I can still feel the pulse quite strongly. I am definately not fat, but from what I've read everywhere else it seems you have to be very thin for this to be a normal thing. Should I be worried that this is an abdominal aortic aneurysm?