Herpes zoster, or shingles, is a reactivation of the varicella-zoster virus leading to a painful unilateral rash, primarily affecting individuals over 45 years. The infection can result in various complications, including postherpetic neuralgia, skin scarring, and ocular issues, especially among immunocompromised patients. Diagnosis is clinical, with treatments involving antivirals, corticosteroids, and pain management strategies, alongside preventive measures like vaccination.