Hello, I am 18 years old and 4 11. I m 115 lbs and I have never had any major medical problems before, other than pleurisy and bronchitis. My entire life I have had an occasional pain in my right leg. It starts behind the knee and then goes all the way up and down my leg. The pain is like an intense cramp and it stays for hours and hours. A few times, I have woken in the middle of the night with a pain so intense I could hardly stand it. This pain was in my calf on the right leg and felt like someone tearing my leg apart from the inside. So I would stand up and put pressure on it and the pain would go away. What could be causing this? My parents have always said it was growing pains but I don t think that s the case.