I have a birth mark thats on about 75% of my body. on my chest theres a red area as well as on my left arm(inward). The rest of the birthmark is lighter than my skin. The bith mark is on the top of my back the back of my arms, lower left side and all the back of my left leg. as a child my parents took me to get studies to see if anything was wrong and nothing was ever found. As i became i teen i noticed my left leg was significantly thinner than the other. a doctor had told my parents the reason for that was the birth mark. can birthmarks have that effect or is it something else that causes my leg to not gain weight? my right leg does have celulities and so does the thin leg why?