Toxic Saliva
Hey, I use my LUNGS to scream, I take my diaphragm completely out of the equation. The Diaphragm is usually used to make the noise go a distance, for volume or length of the scream, lungs are your best choice.
No, You're just dumb as a bag of hammered s**t. Go back to whatever you were doing before you saw this thread, It's not like you're going to contribute anything useful.
Now to OP, Screaming is normal but screaming in a way that sounds good in music and is on pitch, is totally not normal. I would look up a movie called Zen of Screaming to learn to do actual screams. It's important to get this DVD in order to not hurt yourself, really. You can even find it on Youtube.
If you just scream, you're using your throat which is totally wrong. You need to let the air pass through your throat without it being used to shape the tone/sounds if that makes sense. See your vocal chords are about as thick as a finger nail, if that. Any extra stress on them is bad, It's amazing that they can put up with how much talking people do every day even. You must breath more out of the diaphragm and not rely on your throat.
Next up, You can't learn to scream without learning to actually sing first. Screaming is the same thing as singing, but putting a "gimic" type thing on it. You're just making it sound different then it normally would.
Also you don't need to act like your extra tough because your a girl or something. In fact no body gives a s**t
and it doesn't change anything that has to do with singing.