Singer Justin Timberlake announced on Instagram that he’s been diagnosed with Lyme Disease, according to earlier HuffPost reporting.

Timberlake seemed to share the news in response to criticism of his recent tour where fans noticed him not singing while on stage. Timberlake said that, because of his Lyme Disease diagnosis, he experienced nerve pain, sickness and fatigue while on stage, and these symptoms are hallmark signs of the disease.

Below, infectious disease experts share the most common early symptoms of Lyme disease, what happens when it advances, and how to avoid getting it in the first place.

What is Lyme disease?

Lyme disease is spread by ticks, specifically deer ticks in the northeast and midwest and western black-legged ticks in California. It spreads to humans (and pets) through the bite of an infected tick.