Aspirin is an anticoagulant, meaning it reduces your blood's ability to clot. Normally this is an undesirable side effect, because if you're bleeding you want your blood to clot and stop the bleeding.

But heart attacks and other cardiovascular events can be caused by blood clots obstructing blood vessels. Your body's not supposed to let that happen, but for various reasons sometimes it does. When it does, minutes count and you _need_ to tip the odds in your favor.

Fastest way to do that without a hospital is to chew some aspirin. Chewing it breaks through the outer coating that's meant to delay release of the active compound, and dumps anticoagulant into your bloodstream as quickly as possible.

It won't magically solve clots that are already there, but it's putting your finger on the scale. Your body is constantly in a tug of war between biological pathways that want to form clots, and pathways that prevent and dissolve them.

Chewing aspirin is like sending reinforcements to the "pls no clots" faction of your body, as quickly as possible. It stops new clots forming, and existing ones growing. It gives your body some extra margin that it can use to start dissolving the one(s) causing your cardiac event.

It's not a cure, not even close. It's an emergency mitigation that _may_ buy you extra time while paramedics reach you and get you further help.

But trust me, you want to have that option.

Note, this is something you want to have available, but you should not freelance it. If you think you're having a heart attack, embolism or other cardiac event, call 911/999/112/whatever your local version is, tell them where you are and what's happening, that you have aspirin and aren't allergic, and follow their instructions.

In some countries you can buy "low dose" aspirin, which come with slightly different instructions. That's ok too.

This PSA brought to you by: hi! I just had a serious pulmonary embolism, and spent a couple days in intensive care. I'm okay, the immediate danger has passed, though full recovery will take a while longer.

Having aspirin on hand allowed me to begin anticoagulation treatment within seconds of the bad time starting, and 10-60min sooner than waiting for first responders or ER treatment. There's a high chance that was the difference between "scary but you'll be fine" and an obit.