13 y/o son has right leg pain, foot to kneecap. Knee a bit tender to touch, hurts when he walks on it. Feels better at rest. Could it be cardio/vasc?

Unlikely. More com-- Monly he must have bumped his leg/shin into something. Another condition i would like to exclude is traction apophysitis or osgood-schlatter disease, that presents with similar symptoms. He needs to rest it, avoid sports/running etc for about 3-4 weeks ( or more) + advil (ibuprofen) for pain. Get him see an orthopod. Good luck.

Related Questions

I have a haorrible pain on the back lower side of my right leg fron the back of my knee to my heel it is tender to the touch it hurts when I walk?

Calf pain. Is the calf hot, red, swollen? You may have a venous blood clot or an infection of the skin. Both should be checked out at once for proper diagnosis & treatment. Read more...
?DVT. Better get checked to see if you have a blood clot. Ultrasound will make the diagnosis. Read more...
Worrisome. Any pain down the back of your calf that is tender to touch and hurts when you walk should be checked out. Any horrible pain anywhere should be evaluated. Two goods reasons to seek attention. Your symptoms are worrisome. This could certainly be a dvt. Read more...