For kids born before the chickenpox vaccine, getting the disease (and spending hours soaking in a baking-soda bath) was a normal part of childhood. After a week or so, you were back at school and healthy as ever. What you might not have known, however, is that the chickenpox virus never left your body. Instead, it's lying dormant in your nerves, and can reactivate in old age, when your immunity is lower, causing a painful viral infection called shingles.

Test your knowledge about shingles, below:

Shingles is a big deal

"The biggest misconception about shingles is that it's not a big deal," said Dr. Mark Chalberg, the poxviruses program officer at National Institute of Allergies and Infectious Diseases. "Its true that its not, generally speaking, a life-threatening disease, but it can be incredibly painful."

Herpes zoster, commonly known as shingles, causes a painful, blistering skin rash, usually on the upper body, that lasts about two to four weeks. The disease is also incredibly common. One out of every three people will develop shingles within their lifetime , amounting to about 1 million cases per year, according to the Centers for Disease Control and Prevention.

If that doesn't sound bad enough, a small fraction of the people who develop shingles experience searing pain, a complication known as post-herpetic neuralgia, that can last for months or even years after the disease fades. "That pain can be quite debilitating," Chalberg said.

Who gets shingles?

Shingles is caused by the virus that causes the chickenpox. If you've had the chickenpox, the virus is already in your body -- lying dormant in your nerves. Technically, anyone who has had the chickenpox can get shingles at any time, but the risk is much greater for older individuals. As you age, and your immune function decreases, stress to the body can reactivate the virus, causing it to travel to the nerve cells and re-infect the skin.

From age 50 on, you're at an increased risk of shingles, Chalberg said. Anyone in their 70s or 80s is likely to have had shingles, and though rare, the disease that can strike the same person as many as three times.

What you can do

The biggest risk factor for shingles is age. If eternal youth isn't an option, get the shingles vaccine, which has been approved for adults starting at age 50 and is recommended for adults 60 years old and older . Getting the vaccine can reduce your risk of getting shingles by 51 percent and reduce your risk of developing post-herpetic neuralgia by 67 percent .

You should talk to your doctor about what the best time for you to get the shingles vaccine is and about whether or not you are eligible to get the vaccine at all (people who are pregnant, have comprised immune systems, such as those with AIDS, or are undergoing chemotherapy shouldn't get the vaccine ).

"Theres pretty good evidence that the immunity the vaccine provides tends to wane as you get older," Chalberg said. "If you get it too early, youre sort of jumping the gun, and it would really be better to have the highest level of immunity after 60, than after 50."

And while it hasn't been approved by the FDA yet, a new and more effective shingles vaccine may be around the corner. The new vaccine was 97 percent effective in Phase III clinical trials, which were published in the New England Journal of Medicine in April.

Unfortunately, the public health message to vaccinate against shingles doesn't seem to be reaching the older adults who need it most. Only 14 percent of adults older than age 60 received the shingles vaccine in 2010, according to the CDC.

Yes, you've probably had chickenpox

If you are over the age of 40 and have never had the chickenpox, statistically speaking, you're a unicorn. According to the CDC, 99.5 percent of adults older than the age of 40 have been infected with the virus that causes chickenpox, even if they don't remember it.

And even if you had the chickenpox vaccine as a child (those who have are in the minority, since it was only approved by the FDA in 1995 ), you're still at risk for getting shingles as you age. After the chickenpox vaccine was approved, it was primarily given to small children, who are now in their 20s, for the most part, and won't reach the at-risk age for shingles for decades. Still, because the chickenpox vaccine is a live attenuated vaccine, individuals who are vaccinated still run the risk of reactivating the shingles virus as they age -- though the risk is small.

"In the case of the vaccine, it causes a very mild infection and then it becomes latent in nerve cells," Chalberg said.

"It is actually possible for it to reactivate and become shingles, but its such a weakened virus that it doesnt happen very frequently. If you got shingles from the vaccine virus, it would be a mild case of it."

The Centers for Disease Control and Prevention is a great resource for more information about shingles complication, the shingles vaccine and photos of the disease.