How do I know if it's herpes?
You need to see a doctor. Preferably one who has had experience in diagnosing and treating herpes. Although a diagnosis can sometimes be made by visual inspection, visual inspection alone is not a reliable means of dignosis even for physicians. Self diagnosis is even less reliable. The symptoms of herpes vary widely from one individual to another, and many people's symptoms bear little resemblance to the "classic" lesions pictured in medical texts. There are two types of tests that your doctor can use to make an accurate diagnosis.
The first is the viral culture. Under the right conditions, this is the most accurate method. But it has two disadvantages. First, it can only be done during an active outbreak, when the herpes virus is present on the skin surface. Even then, after the first day or two of the outbreak, the chance of successfully culturing the virus goes down, and the chance that the culture will be negative (saying that you do not have herpes) when you actually do have it goes up. So speed in seeing the doctor is essential for a good diagnosis by viral culture.
The second type of test is a type-specific blood test. There are several type-specific blood tests for herpes. The blood tests do not detect the herpes virus itself. They detect the antibodies that your immune system creates to fight the herpes virus. Only the type-specific tests can distinguish between Herpes Simplex Type 1 (which commonly causes cold sores in and around the mouth) and Herpes Simplex Type 2 (which causes most cases of genital herpes). These tests are also accurate, and they have one major advantage over viral culture: a person can be tested at any time, not just during active outbreaks. But they also have their disadvantages.
The major drawback is that unlike the viral culture, these tests can only determine whether you have been exposed to the virus. They cannot determine what part of your body has been exposed. Since some people do have oral herpes from Type 2, and some people do have genital herpes from Type 1, the blood tests can lead to false conclusions. If a person has Type 1 in the genital area, a blood test for Type 2 will be negative. A blood test for Type 1 would be positive, but a person with oral Type 1 and no genital herpes would get the same result. A person with oral Type 2 and no genital herpes would have a positive test for Type 2, the same as a person with genital Type 2. Another drawback is that, since it takes the immune system a while to produce the antibodies, the blood test will be negative for a person who has just contracted herpes.
Where to get the tests
Any physician or clinic should be able to take a viral culture. The physician will need to send the culture to a lab, so the results will take a few days.
There are currently four type-specific blood tests.