I have not grown to the expected height . I am 173 cm. My mother is 173 cm and father is 189 cm. I had a blood test to determine my HGH levels. The doctor asked me for a testosterone and GH test. The result came back a week later and it said that I had a low HGH level and a 21/42 level testosterone . Is this normal for an 18 year old male? I was devastated that my growth plates were closed, because I also had an x-ray of left hand. My doctor asked me whether I am sexually active. I answered him no. But, I got a doubt regarding erectile dysfunction. Am I suffering from erectile dysfunction? Should I be worried? Is my testosterone too low? How can I increase testosterone? I had torsion three years back and nothing back happened. But, this could be a factor. Another factor may be that I used to hold my mobile phone in my pocket all the time .