On this week's cover of PEOPLE, Avril Lavigne opens up about the severe case of Lyme disease that left her bedridden for months. The singer, 30, joins others like Real Housewives of Beverly Hills star Yolanda Foster, who have suffered from the illness and experienced the difficulty of getting properly diagnosed. 

Here is what you should know about Lyme disease: 

1. Lyme disease is contracted when the bacteria Borrelia burgdorferi is spread to humans through a bite by an infected tick. 

"When a tick bites you, it has an anesthetic in its saliva that actually numbs the surface of your skin so you don't feel the bite, and that's why people don't know that a tick is latched onto them and is biting them," says Dr. Erica Lehman, a tick-borne disease specialist. 

2. "If bitten, early symptoms include headaches, nausea, numbness, muscle aches, extreme fatigue and Bell's palsy," Lehman says of the manifestations on the more minor side of the spectrum. Severe symptoms include dementia and arthritis. 

"It can affect people physically, cognitively and psychologically," she continues.

3. It is "the fastest growing epidemic in the world," says Lehman. 

According to the Centers for Disease Control and Prevention, over 25,000 Americans were diagnosed with Lyme disease in 2013, but Lehman says this number is "significantly underestimated" due to factors such as imperfect testing and symptoms that mimic those of Parkinson's, multiple sclerosis and lupus. 

Most New York residents are not aware that tick season is coming earlier this year. Ticks are no stranger to the Capital Region, as their ability to spread diseases. Thomas Pest Services, your tick control expert wants to protect your health, family, friends, children, pets and property from these scary critters. Thomas Pest Services specializes in tick services seasonally and prior to events to reduce mosquito and tick populations. Contact us for your free estimate and inspection today.