From the Care2 news article:
Swollen feet and ankles can cause worry and discomfort. But before you start thinking of the worst, realize that innocent acts like standing for long hours can cause your feet to swell.
Feet and ankles swell when the body retains excess fluid in the lower legs. This can happen due to a number of reasons.
You’re more prone to swollen feet and ankles if your job requires you to be on your feet all day. When don’t move your legs, blood circulation in your legs slows down, and as a result, your feet retain excess fluid.
People who sit for long hours aren’t safe either. Keeping your feet bent for long can interfere with blood circulation.
This kind of swelling can be avoided by moving your legs after every 20 or 30 minutes. Keeping your legs uncrossed can also help.
Read more at the link:
https://www.care2.com/greenliving/7-reasons-you-have-swollen-feet-and-ankles.html