In order to diagnose herpes, a health care provider can swab an area of visibly active herpes infection or, if symptoms aren’t active, a blood test can be given that measures the number of herpes antibodies present in the body. The antibodies don’t indicate herpes itself, but rather show the immune system’s response to the presence of the virus in the body. It’s important to note that sometimes a swab can give false negative results since herpes lesions need to be large enough to yield enough detectable virus and if the outbreak is already healing it also may not be detected in a swab. (6)
Particularly when someone is on suppressive antiviral medication and practicing safer sex, risk of transmission can be greatly reduced. Cullins suggests female condoms (condoms that go inside the vagina and cover most of the vulva, though it's important to note that not all people with vaginas are female) to provide the most protection against transmission, though condoms that go over the penis will protect what they cover.
It can be pretty similar to having flu, Michael says. "When you are infected with herpes you can experience symptoms like fever, muscle aches, swollen lymph nodes, and a general feeling of being unwell." However, many people will not have any symptoms at all - which means until someone notices blisters or sores, they might not realise they have a herpes infection.
A doctor will base a presumptive diagnosis on information provided by the patient and on the physical examination. The characteristic appearance of the herpes sores leaves little doubt about the diagnosis, so the typical appearance of the sores is key to the diagnosis. This appearance helps distinguish oral herpes from oral thrush, shingles, gonorrhea, and syphilis. In addition, chapped or sunburned lips can resemble oral herpes, but the tissue stain (Tzanck smear, see below) shows no virus-induced cell changes. Further testing is usually not necessary but is sometimes done.