Welcome back to Mid-Week Meditations, Lifehacker's weekly dip into the pool of stoic wisdom, and a guide to using its waters to reflect on and improve your life.

In the 16th Century, over the course of five years, almost 80% of the Aztec population were wiped out due to an unknown disease that burnt through their villages, causing high fevers, bleeding from the mouth, nose and eyes and eventually lead to death. Without understanding the epidemic, the Aztecs named the phenomenon 'cocoliztli', their native word for 'pestilence'.

Scientists have pondered the potential cause of the cocoliztli epidemic for years, but only recently has new research uncovered what may have caused it.

There’s been a lot of interest in the harmful effects of prolonged sitting at work, from academics and the public alike. The attention being paid to sitting — or rather, not sitting — while on the job stems from the scientifically validated message that being sedentary in general, both indoors and outdoors, is bad for your health.

However, comparatively little attention has been devoted to the harmful effects of prolonged standing at work, despite past studies linking it to chronic back pain and musculoskeletal disorders (MSDs) in the lower limbs. What’s more, research has shown that prolonged standing might increase the risk of cardiovascular disease.

Angelina Jolie revealed in a Vanity Fair interview that she developed Bell's palsy last year, causing paralysis on one side of her face. This condition can come on suddenly, but tends to resolve itself within weeks to months. (Jolie has since recovered.)

Food poisoning sucks, but if you do get it, you should know how to figure out which type it is, what you're in for, and the best way to deal with it so you can feel better.

Video: Sexually transmitted diseases aren't rare -- half of us will have one at some point in our lives. It's important to tell your partner if you find out you have one, and this video from Planned Parenthood shows you how.

A once-dormant killer cat virus has flared up again in Australia, hitting Sydney’s domestic cat population. To date, there have been more than 50 confirmed deaths. Here's everything you need to know about the disease - including the symptoms to look out for and the best ways to prevent infection.

One of the funniest moments in Toy Story 3 was when Woody surreptitiously placed a sheet of paper on a public toilet seat in the midst of a daring escape. It was funny because it was relatable. But are public toilet seats actually any dirtier than the ones in your house? The answer's in the headline.

There's a new flu shot every year, to match the particular flu strains floating around. Some years the shot isn't a good match. Even so, the flu shot is still a good bet.

Skin infections like MRSA and other illnesses can easily spread in gym and locker room settings. You probably already know to wash up after hitting the gym, but pay special attention to washing your hands. It's no fun to come down with something avoidable during your pursuit of health.

If you grew up in the 1990s, you practically absorbed a degree in AIDS studies just by existing -- or at least that's what it felt like. The years since then have brought better tests and treatments, and we now know more about the virus, but that information isn't common knowledge. HIV and AIDS have fallen off our radar.

Zika virus, a previously obscure disease that had only caused a handful of cases in Africa and some island nations, is now a major global health concern. It's been linked with brain damage in babies, and the World Health Organisation just declared South America's Zika epidemic a public health emergency. You may not live in South America, but in today's world of global travel and fast-moving infections, let's talk about whether you need to worry.

Have you ever held your breath when someone coughed? Or tried to flush the toilet with your foot? Some of these tricks might help if you do them the right way, but they're often unnecessary and based mostly in paranoia. Here's the truth about avoiding germs in everyday life.

Ever since Seinfeld tackled the topic in 1993, we've known that double-dipping is socially unsavoury. But is it really a viable way for disease-carrying germs to spread? Well, of course it is.