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.

If untreated, Lyme disease can lead to a cascade of complications, including fatigue, severe headaches and neck stiffness, arthritis, rashes and heart palpitations. Patients can also experience dizzy spells, shortness of breath and nerve pain. In rare cases, Lyme can lead to meningitis.