Shingles (herpes zoster) is a viral infection that may cause pain, burning, or a tingling sensation on either the left or right side of the body. Several days or weeks later, a band, strip, or small area of rash usually appears in the same area and progresses into blisters, which scab over before clearing up over the next few weeks.

Shingles develops from the virus that causes chickenpox (varicella-zoster virus). The virus remains in the nerve tissue and can become active again in anyone who has had chickenpox. Shingles is most common in older adults and people who have weakened immune systems because of stress, injury, or other factors. No one knows what makes the virus active again.

A person with shingles can spread the virus until the blisters have scabs. The spread of the shingles virus can cause chickenpox in those who have not had it before and have not been vaccinated.

Medicines may relieve discomfort from the rash and pain. Some people have pain that lasts after the rash is gone (postherpetic neuralgia).

The shingles vaccine can help prevent shingles or make shingles less painful.