Justin Timberlake opens up about his health, revealing a 'relentlessly debilitating' Lyme disease diagnosis as he bids farewell to his world tour.

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.

Justin Timberlake today shared with fans that he's "been battling some health issues," including Lyme disease.