Vulcans' unique physiology means their blood appears green instead of red, like humans in the Star Trek franchise.

Because blood vessels run across the surface of the retina instead of beneath it, it's easy for the vessels to proliferate or leak and impair vision. So, the evolution theorists say, the anti ...

The sickle cells can become trapped in small blood vessels, resulting in organ damage, and they rupture more easily, leading to anemia. Today, despite the detailed molecular explanation of the ...

To understand the events that unfold in the finale of "The White Lotus," look at the conversation Chelsea and Rick have over ...

This is when a so-called “blood moon” lunar eclipse plays out, visible in North and South America, parts of Africa, the Pacific, and Europe. So what causes a lunar eclipse, when is the best ti ...