Why do my hands swell when I run?

Question

I’ve just started running as a part of my workouts and noticed that my fingers swell up during my run. I know some people’s hands swell easily, but mine have never really done that. Could this possibly be a sign that I’m getting dehydrated? Why do my hands swell when I run?

Answer 1

It’s not unusual for your hands to swell when you run because running causes increased blood flow to your heart, lungs, and muscles being worked out. This increased circulation to certain areas actually decreases to your hands, which will lower their temperature. In order to try to return to a normal temperature and help circulation, the blood vessels in your hands will naturally open wider. When this happens, it can be seen as swelling. If your fingers in particular appear to be swelling the most, this can happen from hanging your hands below your heart while running. Basically, your body is too busy increasing circulation to your largest muscles when you run that the smaller ones, like your hands and fingers, become less efficient in moving excess blood and fluids, which is why your hands swell.

Answer 2

Why do my hands swell when I run? It is because overall, your blood travels through your arteries to the tissues in your body and then returns to the heart through the veins. This circulation is caused by the pumping of the heart and the contraction of the larger muscles. Blood vessels aren’t solid structures though and have permeable membranes that allow some fluids to leak into the tissues and drain into the lymphatic. This happens because of a difference in pressures between the vasculature and the tissues, so a balance will try to be achieved. Sometimes when these pressure gradients become more diverse it will cause a buildup of fluids in the tissue. When your arms are held in a downward position for a long time and there’s not enough muscle pumping action to increase circulation, it can cause swollen hands because of this pressure gradient. So, if you run with your arms in a downward position the whole time then it can cause your hands to swell. Luckily, this is completely not harmful and can be reversed by elevating your hands so the excess liquids can drain.