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Health | Diseases & Conditions | Rare Diseases

Rare diseases may not be common, but they are no less painful or difficult than conditions you've heard of. Learn about the causes and symptoms of rare diseases as well as how patients can find treatments for their unusual conditions.

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What are the world's rarest diseases?

What if you were the only person in the world with a disease, and scientists used your name to classify it? How would doctors know what was wrong?


10 Diseases Named After People

 10 Diseases Named After People

Some scientists get the recognition they deserve — in the names of diseases they found. Learn about 10 diseases named after people at HowStuffWorks. See more »

Quiz: Real Historical Disease or Made-up Malady?

 Quiz: Real Historical Disease or Made-up Malady?

Sometimes it's hard to tell the difference between real historical diseases and made-up maladies. Test your knowledge of both with this quiz at HowStuffWorks. See more »

Human Parasite Quiz

 Human Parasite Quiz

Parasites can plague even the healthiest human. Test your knowledge of them in this human parasites quiz. See more »

Rare Disease Quiz

 Rare Disease Quiz

How much do you know about the world's least-known diseases? Find out in our rare disease quiz. See more »

Alone We Are Rare, but Together We Are Strong: Orphan Diseases Quiz

 Alone We Are Rare, but Together We Are Strong: Orphan Diseases Quiz

Orphan diseases are rare, but they are still serious conditions. Test your knowledge of orphan diseases with this quiz at HowStuffWorks. See more »

The Oldest Diseases of World Quiz

 The Oldest Diseases of World Quiz

Take this HowStuffWorks quiz to learn all the horrible diseases you might've expired from in ancient times and the ones still around today! See more »

Frequently Asked Questions About Proteus Syndrome

 Frequently Asked Questions About Proteus Syndrome

Proteus syndrome causes atypical development of bone and tissue, leading to physical deformities. See these frequently asked questions about Proteus syndrome. See more »

Frequently Asked Questions About Neurofibromatosis

 Frequently Asked Questions About Neurofibromatosis

Neurofibromatosis is a genetic disorder that causes tumors to form on nerves throughout the body. Learn more about neurofibromatosis here. See more »

Top 10 Rare Diseases

 Top 10 Rare Diseases

Rare diseases are usually genetic, but environmental factors can play a role. Take a look at the top 10 rare diseases that you may never have heard of. See more »

20 Diseases You've Probably Never Heard Of

 20 Diseases You've Probably Never Heard Of

There are many diseases out there you've never heard of. We've put together the top 20 diseases you've probably never heard of that are rare and unusual. See more »