A needle puncturing flesh and delivering bright red blood from your vein into a test tube — that’s one thing that might make someone faint. So could intense pain; extreme emotional stress, like heartbreak; or fear in other types of situations, such as seeing an insect you’re afraid of.

But terrifying events aren’t the only thing that can send you over the edge. Plenty of weird and obscure medical episodes can as well.

Peeing

When your blood pressure drops drastically during or right after urination, it’s called micturition syncope, although doctors don’t fully understand how it happens. “It may be related to opening of the blood vessels that occurs when getting up and standing at the toilet or that occurs at the rapid emptying of a full bladder,” the Mayo Clinic says. “This is thought to result in a sudden drop in blood pressure.”

The organization also says that the condition usually affects older men, particularly “at night after a deep sleep.”

Read: What That Blood Means, By Color and Location

Standing up

You blood pressure may also drop too low when you stand up, because of a condition called orthostatic hypotension. “When you stand up after sitting or lying down, gravity pulls blood down into your legs, which reduces your blood pressure,” the U.K.’s National Health Service explains. “The nervous system usually counteracts this by making your heart beat faster and narrowing your blood vessels. This stabilises your blood pressure.” But when people have orthostatic hypotension, their body doesn’t compensate and the brain gets less blood, which could lead to fainting. Dehydration increases this risk.

The Mayo Clinic calls the condition “often mild, lasting a few seconds to a few minutes after standing.”

Is fainting better or worse than Lizzing? Credit: 30 Rock

Violent coughing

This source of fainting has been studied for a long time, with people originally thinking the sufferers had epilepsy, according to an article in Respiratory Medicine. Experts now see it as a result of quick changes in blood pressure.

Much like the peeing-induced fainting, this situation also more commonly affects men: “A typical profile of the cough syncope patient emerging from the literature is that of a middle-aged, large-framed or overweight male with obstructive airways disease,” the article says.

Read: Strange Causes of Bruising

Laughing

How can something so wonderful have such negative consequences? It’s rare, but it’s possible that intense laughter could cause you to drop like a sack of potatoes. An article in the Journal of Medical Case Reports says the condition “likely goes unrecognized by many health care providers,” and links it to the pressure of the many forced exhalations it would cause in the amused individual, again affecting blood pressure. “Normally the body is able to compensate for these changes,” but the authors have noted five cases in which adults have passed out from laughter.

You're Busted Credit: Arrested Development

Pooping too hard

It’s the strain that does it. Men’s Health describes what goes on in your body during that hard push to poop: “When we get ready to drop one … you take in a deep breath and hold it, before trying to exhale against your closed-off airway.” Your lungs expand, you push down on your diaphragm and pelvis and your anus magically opens to let out that huge poop.

As you are doing this, the magazine explains, less blood flows to your heart and brain. You’re more likely to faint if you already have heart issues, but if you’re worried, “reduce your risk of constipation, so stool comes out more smoothly with little straining.”

See also:

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Deadly Poisons That Are Also Medicine

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