Why the Zebra?

You may have heard the phrase “When you hear hoof beats, think horses and not zebras”.

This phrase was coined in the late 1940s by Dr. Theodore Woodward, professor at the University of Maryland School of Medicine. He was using it to illustrate to his medical student interns that while the more exotic and rare diagnosis can be more exciting to diagnose, it’s often a more mundane and simple explanation. If you hear hoof beats in Maryland, it is more likely to be a horse than a zebra.

Though both animal will create the same sound, it is more logical to assume it is the animal that is more common to the area. Similarly, if you go to your doctor complaining of fatigue and a sore throat they should check for something like allergies or mononucleosis rather than jump to testing for lupus. The most common answer is most often the correct one.

The problem arises when something rare and exotic really does occur. When someone (like me) gets diagnoses with a rare problem…then everything has to be looked at differently. We can no longer assume that fatigue and a sore throat is allergies or mononucleosis, though it’s still important to check for the run of the mill problems. The rare becomes our normal. We have to check that our organs are working rather than assume it’s obviously a simple cause. Each minor problem has to be treated…well…like we’re not your average horse.

So many groups of people diagnosed with rare diseases have adopted the idea of a zebra as an unofficial mascot. One in particular, the Ehlers-Danlos Syndrome sufferers (again, like me) have made it a bit more official and the animal is now the logo for the Ehlers Danlos Society. Because if you can’t fix it, might as well embrace it and make it a friend.