the symptoms that you can get from using hgh vary based on the amount you take and the length of your cycles. they arent the same across the board for every user.
HGH & acromegaly
acromegaly is the enlargement of bones and organomegaly is the enlargement of organs in the body
* HGH (Human Growth Hormone) Effects
in other words with the pic you just put up with bolt you are saying he is on roids as well as
some other symptoms of hgh use include things like acne on the face and body, teeth spreading, and hair loss. it also increases muscle while getting rid of fat creating an almost unrealistic comic book like physique. these kinds of things obviously arent caused exclusively by hgh (you might have always looked like a caveman, had spread out teeth, acne, and a comic book body) but when you see these effects in an athlete, especially several of them in conjunction with each other, its an immediate warning sign.
rg3 for example has the protruding jaw and brow, extremely low body fat per body muscle ratio, acne, and the characteristic thick abdominal wall caused by organomegaly, what some other posters have pointed out as "roid gut"
the difference of a normal abdominal wall and a thick abdominal wall caused by organomegaly is someone like floyd mayweather vs roy jones (floyd has very ripped abs but they dont protrude out and look thick meanwhile roy's abs are ripped the same way but in addition have an extra characteristic look of thickness and protrusion) and allyson felix vs carmalita jeter (same example)
heres a picture of usain bolt's abs which is rare since he usually wears a shirt that hides his body instead of a track suit. make of it what you will.
heres a photoshop comparing two body builders. on the left is ronnie coleman who takes hgh and sharzaneggar who was taking some earlier form of steroid before the hgh era