Across life on Earth, blood comes in red, blue, green, purple, even clear. But why? And what makes your blood different from mine? This video will teach you everything you need to know about the strange world of blood—what it does, why...

Organ transplants save lives, but they come with challenges: every minute a healthy donated organ is on ice increases risk. And even if things go perfectly, rejection of the organ is still possible. Cardiothoracic surgeon Abbas Ardehali...

Quick Questions explains why, when it comes right down to it, there are really only eight kinds of people in the world.

You’re probably aware that your blood can be A, B, AB or O, but it turns out that blood types can get a lot more complicated than that! *We made a mistake in the credits of this video: The writer of this episode was Alane Lim.

From A positive to O negative, everyone's born with a blood type, and they're stuck with that blood type for their whole lives... or are they?

If you've ever wondered why you crave certain foods or what your appendix actually does, there's something in this collection for you!

In 1881, doctor William Halsted rushed to help his sister Minnie, who was hemorrhaging after childbirth. He quickly inserted a needle into his arm, withdrew his own blood, and transferred it to her. After a few uncertain minutes, she...

Two SciShow hosts go head-to-head in a battle to figure out who will be the reigning champion for this era of SciShow Quiz Show!

Your cells are coated with sugars that store information and speak a secret language. What are they trying to tell us? Your blood type, for one -- and, potentially, that you have cancer. Chemical biologist Carolyn Bertozzi researches how...

Did you know that your blood type affects more than just who you can donate blood to?

Learn how to set up and solve a genetic problem involving multiple alleles using ABO blood types as an example!

Researchers have revealed a potentially life-saving rapid blood type test, and does using GPS to get around make your brain lazy?

From A positive to O negative, everyone's born with a blood type, and they're stuck with that blood type for their whole lives... or are they?

You’re probably aware that your blood can be A, B, AB or O, but it turns out that blood types can get a lot more complicated than that!

The idea of putting blood into a person was a radical one when it was first attempted 350 years ago, but today, more than 15 million pints of blood are donated each year in the U.S. to be used in transfusions to over 5 million patients. ...

Quick Questions explains why, when it comes right down to it, there are really only eight kinds of people in the world.

Now that we've talked about your blood vessels, we're going to zoom in a little closer and talk about your blood itself. We'll start by outlining the basic components of blood -- including erythrocytes, leukocytes, platelets, and plasma...

Paul Andersen explains the importance of blood types in blood transfusions. He starts with a brief discussion of blood antigens and antibodies. He describes how the ABO differs from the Rh blood type. He shows you how to solve simple...

Hank gives you at least three reasons to like mosquitoes even less than you do already, and tells you how you can literally decrease world suck by fighting mosquito-borne disease.

Howcast -Learn how to lose weight on the Eat Right for Your Type diet from Carolyn Dean, M.D. in this Howcast video.

Howcast -Learn how to lose weight on a vegetarian diet from Carolyn Dean, M.D. in this Howcast video.

Howcast - Learn how to say "my blood type is" in Greek with this Howcast video.

Howcast -Learn how to say "I need a doctor" in Polish with this Howcast video.

There are several reasons why some people are more prone to mosquito bites than others. First of all, mosquito attraction is partly genetic. Some people have genes that make them more attractive to mosquitoes than...