Hello, I have a lump under my chin that doesn't seem to be fat but maybe muscles. I have also noticed that the bump increases in size when I press my tongue hard against my palate. I would like information on what this could be and what type of healthcare professional I should consult to get an accurate diagnosis and determine the best treatment option. I am under 25 and i'm athletic and lean enough to have visible abs. Note: tongue posture is up.