What are those "bruises"?

I noticed that whenever I suck on my arm for resembling 10 seconds, my skin turns darkish-brownish...It is not a bruise, it doesnt even hurt, but the color tweaking, why is that?What are those "bruises"?
from the sucking you are breaking small veins inside and bringing blood to the surface of your skin =silly piece to do really
because your giving youself a hickey. Let me guess your age. 14?
They are right a hicky, bringing blood to the skin.
UH, how old are you? 12?
It's a hickey you dumb sh!t. You are breaking blood vessel under the skin and they show up as, what is commonly call, a hickey.
GOD YOU'RE STUPID!
It's a hicky! stop sucking on your arm!!