Today i had to be standing the whole day , and i am obese so of course i got pain in both of my legs but i notice too that my knee have a little bump in the front and is red in the back, is itching in the back as well what can that be and what to do?

The bump could be a dilated superficial vein. Redness&tching suggest skin reaction to something that came in contact with your skin. I recommend elevating your legs to help mobilize any fluid that has accumulated in your lower extremites. Avoid salt. For the itchy area apply cortisone type ointment. See your MD if spreading redness, pain or tenderness develop. Wear elastic stockings when standing

Not sure without seeing it. What to do? For every pound about ideal BMI (25) you are carrying around 4 sticks of butter and this puss pressure on your knees and they wear out. So is you are 20 lbs over weight you are carrying 80 sticks of butter and it is pounding you knees. My suggestion is to get BMI down to 25 and it will stop.