The test looks for antibodies created to attack the virus. Blood testĪ blood test can also be used to diagnose HSV. The fluid will be examined for herpes and to see what type of HSV is causing the infection. If your sores or blisters are producing fluid, a healthcare professional can take a sample of the fluid and send it to a lab. Tests performed by a laboratory are needed to confirm a diagnosis of any kind of herpes. Identifying red, itchy bumps or blisters along with fever, body aches, or swollen lymph nodes may prompt a medical professional to test for the presence of the herpes virus in your body. To diagnose herpes on the buttocks, a doctor may first look at the physical symptoms you’re experiencing.