Most people associate a fever, high or mild, with a viral infection. While this is generally true, not all viral infections lead to fever in all people. In fact, some viruses can manifest without a fever, often to the detriment of the person infected. Knowing the viruses that can cause symptoms without a fever is important to your health. As with any medical condition, if you suspect you are ill from a virus, you should seek medical attention immediately.
The H1N1 virus, or "Swine Flu," is an unusual virus in that it sometimes does not cause flu-like fevers in some victims. Relatively young and healthy people are most likely to die from H1N1 virus simply because they do not have a fever which they rightly assume indicates illness and thus ignore the symptoms. Often, the virus does manifest respiratory symptoms, such as cough, sore throat, stuffy or runny nose. Also, most patients report body aches, lethargy, chills and headaches.
Shingles is a skin irritation, or "rash," caused by a virus that is closely related to the virus that causes chickenpox. Also known as the herpes zoster virus, shingles is more common in people over 50 and the risk of contracting shingles increases with age. Also those with compromised immune systems are more likely to contract the virus. Symptoms invariably include a bright red, bumpy rash accompanied by pain, sometimes intense. In the rarest of cases, shingles can cause blindness, pneumonia, hearing loss, and even death. Luckily, the virus is one which usually results in a single episode and only if the patient has had chickenpox before. If they have not, instead of shingles, they may develop chickenpox.
Herpes simplex 1
Also known as cold sores, herpes simplex is a viral infection which usually presents no outward symptoms upon primary infection, that is the first time you are exposed to the virus. Only later recurring outbreaks once you have been infected manifest as physical symptoms. Some of the symptoms include sores on the lips, swollen or sensitive gums, sore throat, swollen glands of the neck, nausea, dehydration, headaches, and excess salivation or "drooling." Sometimes cold sores are preceded or accompanied by fever, but not always.
Genital herpes is cause by the herpes simplex 2 virus and is a sexually-transmitted disease which can manifest without a fever. Prevention of most venereal diseases is aided by the use of condoms, but condoms are not a perfect barrier, so you may develop symptoms after sexual intercourse with an infected person. Symptoms include painful urination, lesions on the genitals, vaginal discharge, a feeling of exhaustion or tiredness, swollen lymph nodes, and blisters in the groin and other areas.
The Rhinovirus, which commonly causes colds and flu-like symptoms in most people every year, can manifest without an accompanying fever. Any person is susceptible to the Rhinovirus, but typically the young, elderly, and those with weakened immune systems are most at risk. Symptoms include sneezing, runny nose, stuffy nose, sore throat, loss of voice or "laryngitis," headaches, and sinusitis or inflammation and pain of the sinus cavities of the head. Typically, the best course of action for Rhinovirus infection is rest and fluids, though some over-the-counter medications claim to shorten the intensity and duration of Rhinovirus infections.