Herpes zoster is mainly diagnosed by symptoms, mainly physical examination, and the main points are as follows: 1. there are generally low fever, tiredness, general malaise, loss of appetite, and local skin itching, burning sensation and other prodromal symptoms; 2. the rash is mostly distributed along a certain peripheral nerve, with the intercostal nerve and trigeminal nerve being the most common, mostly occurring on one side of the body, not exceeding the midline, and rarely involving both sides; 3. the rash mostly starts with erythema, and soon appears on top of the erythema or on normal skin. The blisters appear on top of the erythema or on the normal skin in clusters, with redness at the base and around, and the blistering fluid is initially clear, but later may become turbid or hemorrhagic, while the stroke-type may only have erythema and papules; 4.