What Causes Bruises On The Upper Thigh?

I have been on a meth binge for about five days taking Xanax in the morning go get a few hours of sleep in. I have used meth in the past rarely. For the first time though I am having random and fairly small bruises appearing on my upper thighs all the way to the back of my calves. Back pain I know is normal but the brusing and feeling of my hands and sometimes leg cramping concerns me. Any info?