An estimated 400,000 Americans are diagnosed with Lyme disease each year, and Lyme is spreading through temperate climates around the world, including in the United Kingdom, Europe, Asia and Scandinavia,” says John Aucott, M.D. , director of the Johns Hopkins Lyme Disease Clinical Research Center .

Understanding how to prevent Lyme disease, watching for the signs of the condition and learning more about current testing will go a long way to maintaining your health.

Avoiding Lyme Disease

There aren’t any vaccinations for Lyme disease, but you can be vigilant and avoid getting bitten. Ticks live in brushy and tall grass on the edges of your yard, green areas within the city limits and in the woods. “Pets also bring ticks into the house, so we usually tell people to avoid letting their cats and dogs sleep in bed with them,” notes Aucott.

Check yourself frequently for ticks, particularly behind your knees, underarms, belly button and anywhere clothing presses on the skin. Ticks are particularly active from March through November.

Learn what you should do if you find a tick.

Recognizing the Signs of Lyme Disease

“Lyme disease presents differently depending on how long it has been in your system,” Aucott says. “The first stage typically lasts a week or longer. It begins as a skin infection, and about 80 percent of people will develop a round, red rash that expands — but it’s not always the trademark ‘bulls-eye’ rash.”

Some people may develop a fever, chills or the flu. “If you think you have a summer flu, it isn’t influenza — influenza comes in the winter months. If you develop a fever or generalized musculoskeletal, you should see your primary care doctor about the possibility of having Lyme disease.”

As bacteria leave the skin, they spread to the blood stream, muscles and joints. “If left untreated over the course of several months, Lyme disease can cause severe health issues, including a slower heart rate or facial nerve palsy, and 60 percent of people will develop Lyme arthritis, a particularly painful swelling in the joints,” says Aucott.

Understanding Current Lyme Disease Tests

When a tick transfers Lyme disease to your skin, your body increases its production of antibodies to fight the infection — a process that takes several weeks. Current Lyme disease testing is based on measuring the number of antibodies in your system. If you’re tested for Lyme disease during the time it takes your body to ramp up, it’s quite possible the test may come back negative, especially in the early days.

“Since the antibodies are the basis of the diagnostic test, it may not work that well initially. So don’t ignore the diagnostic Lyme disease rash even if the test is initially negative. It’s incredibly important for you to talk to your primary care provider if you start seeing potential symptoms for Lyme disease,” cautions Aucott. “You’ll want to start on antibiotic treatment as soon as possible.”