It's fun to take a hike through the woods: listening for songbirds, looking at wildflowers, spying the occasional chipmunk. You also need to keep an eye out for the bane of hikers—poison ivy. Find out how much you know about this annoying plant by taking this true-false quiz.

Bacterial pneumonia kills thousands of older Americans each year. Yet there is a vaccine that offers protection against this deadly illness. How much do you know about pneumonia and the vaccine?

Dogs and cats and birds and hamsters. Snakes and guinea pigs and turtles. The family pet can be a source of joy and companionship, no matter what kind of animal it is. Sometimes, however, your favorite animal can be a source of illness. Learn more about pets and disease by taking this multiple-choice quiz.

This illness has existed for thousands of years. Learn more about Parkinson disease by taking this quiz.

True or false: If the regular dose of OTC pain reliever doesn't relieve your pain, it's safe to take more.

What's the most sensitive part of your body? Are women less sensitive to pain than men? Does everyone feel pain? Get answers to these and other questions by taking the pain quiz.

True or false: A cut heals most quickly when exposed to air.

Answer this one: West Nile virus belongs to a group of viruses known as flaviviruses. How are these viruses spread?

Answer this one: How far in advance of your overseas trip should you visit your doctor for vaccines?

Many Americans take vitamins, minerals, or other dietary supplements every day without knowing enough to ensure optimum results.