I've had portal hypertension since I was about 14 and now I'm 21. It's because I have liver cirrhosis so the blood doesn't flow properly through the liver. It's caused my spleen to become very enlarged and my liver is also bigger than normal. The spleen is not a problem, just annoying. But with the hypertension, your son may have to have yearly endoscopies done to make sure there are no bleeds in his esophogus. I know way too much about the liver haha. So if you have questions, feel free to ask me. As long as you keep on top of things, the hypertension shouldn't be too big of a deal.