Herpes zoster, or shingles, is caused by the same virus(varicella zoster) that causes chickenpox. After an episode of chickenpox, the virus becomes dormant in the body. Herpes zoster occurs as a result of the virus re-emerging after many years.
The cause of the re-activation is usually unknown, but seems to be linked to aging, stress, or an impaired immune system.So stress and anxiety can reactivate the virus.
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