Eli5: what’s happening, and what’s it called, when you hold your breath, squeeze your head/face, resulting in turning red and veins popping out… like that meme?

Question

Biologically speaking, what’s happening? Is there a name for this? And surely I creates some health risks, right?

In: 3

Answer 1

You are “manually” increasing your blood pressure by squeezing your muscles around your body’s blood reservoirs. Blood vessels, veins, capillaries are all stretchy tubes, so when the pressure in them goes up, they swell/bulge and “pop out”, and you go red (from the capillaries just under your skin also swelling larger).

And no, it’s not good for you. Could burst an aneurysm for example.

Answer 2

You are doing something called a ‘Valsalva” maneuver. Basically, by holding your breath, and unconsciously closing the valve at the top of your windpipe, you are increasing the pressure inside your chest. This also increases the pressure in the veins that drain blood from your head, so the blood backs up, making your face redder and more congested. The other answer about blood pressure going up and causing aneurysms is completely wrong. The effect on your arteries (where blood pressure is measured) is for your blood pressure to actually go down.