HSV-1 has been proposed as a possible cause of Alzheimer's disease. In the presence of a certain gene variation (APOE-epsilon4 allele carriers), HSV-1 appears to be particularly damaging to the nervous system and increases one's risk of developing Alzheimer's disease. The virus interacts with the components and receptors of lipoproteins, which may lead to its development.
Most people with genital herpes have no symptoms, have very mild symptoms that go unnoticed, or have symptoms but do not recognize them as a sign of infection. Genital herpes symptoms include blisters, sharp pain or burning feelings if urine flows over sores, an inability to urinate if severe swelling of sores blocks the urethra (tube from the bladder to outside the vagina), itching, open sores, and pain in the infected area.
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.