Herpes is diagnosed by, either, looking at visible sores or by taking a sample for lab testing. Blood tests look for antibodies toward HSV-1 or HSV-2 can be done even between breakouts. Your care provider can help you to arrange for testing under your health insurance plan. However, private testing is also available.
Please visit your doctor for diagnosis if you suspect you may have contracted Herpes Simplex Virus. Most doctors are competent to accurately diagnose HSV by signs and symptoms, even without running any lab tests.
As embarrassing as it may be, there is a definite benefit attached to actually having seen your doctor for diagnosis, rather than ordering commercial test kits online. It is completely possible that what you think is an initial outbreak isn't. You can be infected and have no immediate symptoms. In fact, you can be symptom free for weeks, months and years.
The benefit of visiting to your doctor's office is that your doctor can run a blood test to find out if there are antibodies in your blood. If there are no antibodies then your infection is brand new. If there are antibodies, then your infection is not new. It means you have had herpes for at least 3-4 months. This information can be helpful in understanding when you contracted herpes and, possibly, from who if you have had more than one sexual partner.
Cell cultures obtained from swabbed, active blisters is the typical way of testing for HSV. First time lesions contain a larger amount of virus in the cells. Recurrent lesions have a very high false negative rate, so it's important to be tested during your first breakout to accurately determine which type of herpes you have. Knowing what type you are dealing with is the second advantage to seeing your doctor, rather than ordering private tests.
Still, private testing available, so not even your doctor (or your insurance) needs to know anything. But, before you contact a private lab read through the information below.
Blood tests do not look for the herpes virus. They look for antibodies. They cannot identify the type of herpes you have, where it is located or how long you have been infected.
It can take up to 3 months for antibodies to develop in the blood, so the best time to be tested for HSV is between 3-4 months after your first breakout (or of being concerned you may have contracted herpes from a suspected partner). Blood-testing any earlier than this may result in false negative.