The tick-borne disease—which singer Justin Timberlake revealed this week he has been suffering from—is increasing in the U.S. both in range and frequency.

As pop star Justin Timberlake concluded his world tour earlier this week, the “SexyBack” singer shared on Thursday in a social media post that he has been grappling with health issues and a diagnosis of Lyme disease.

Lyme disease is spread by black-legged ticks that are found across the country, including Washington state. Here's how to spot and treat the symptoms.