i also have a question lately my knees hurt for example when i stand or sit for to long is it the joints closing because it happens at odd times or with gaps in between so when i see i want to see a doctor it goes away
This is common for boys who are in their growth spurt or have just finished it. The cause is the thigh muscles are stretched and are pulling on the point where the muscle attaches to your lower leg. It is called Osgood-Schlatter (after the two doctors who defined it). A noticeable characteristic of it is a bump just below the knee that is tender. It will eventually go away on its own, but until it does, pay attention and don't over do it.
I looked at my sister's knees and my dad's knees you can see the bump on my my sister and my dad doesn't have that. I would say the area around the bump is tender but dead center it's hard but it does not feel like bone. I am confused. Is that what's causing the problem of my knees hurting because I am still growing or would you say it is serious? Today after gym we just went outside. We hardly did anything and the right knee was hurting.
Osgood-Schlatter disease isn't really a disease. It is a repetitive injury that comes because your quadriceps come over your knee cap and are connected to your shin just below the knee cap. When you are growing rapidly, this connection weakens and is prone to strain injuries, especially in someone who is athletic. It is estimated that 1 out of 5 boys experience this problem.
It resolves itself once you stop growing. When it pains you, you should give your legs some rest. Some ice on the area can help keep the swelling down. It is especially important that you stretch your quadriceps (the big thigh muscle in front).
Standing Quad Stretch [ExRx.net]
Lying Quad Stretch [ExRx.net]
Levered Quad Stretch [How Stuff Works]. This can also be done with the back foot on a chair or sofa to stretch the quads further.