American Medical Association Family Medical Guide - American Medical Association [642]
Symptoms
Some symptoms of CFS resemble those of viral infections, such as a sore throat, tender lymph nodes, muscle pain, joint pain (without swelling or redness), and headaches that are different than usual. A person who has CFS can also experience significant impairment in short-term memory or ability to concentrate, feeling tired even after sleeping for several hours, and fatigue that can last 24 hours after physical exertion. Some people develop psychological problems such as anxiety (see page 718) or depression (see page 709).
Diagnosis
CFS is difficult to diagnose because the symptoms resemble those of many other disorders. Also, there are no laboratory tests or imaging procedures that can be used to help make a diagnosis. Your doctor will take a detailed health history and perform tests to rule out other possible causes of your symptoms. Before a diagnosis of CFS can be made, you must have experienced chronic fatigue for at least 6 months along with at least four of the symptoms described above.
Treatment
Although the cause of CFS is unknown, it is possible to treat many of the symptoms. For example, your doctor may prescribe aspirin, ibuprofen, naproxen, or another nonsteroidal anti-inflammatory medication to help relieve headache, muscle aches, and joint pain. Most people who have CFS recover; their symptoms go away and they eventually return to their usual level of activity.
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Infections and Infestations
Infections are caused by organisms—including bacteria, viruses, fungi, and protozoa—that invade the body and multiply once they are inside. The course of an infection depends on several factors, including the nature of the infecting organism, its ability to cause disease, where it enters the body, how it spreads through the body, and the speed and effectiveness of the body’s response to it. Disease-causing organisms require favorable conditions to cause infection—such as the right temperature, enough moisture, and a supply of nutrients. Viruses require suitable cells to invade and multiply in.
The immune system is a group of cells and proteins that can recognize foreign proteins (antigens) in the body, seek them out, and destroy them. The immune system attacks invading organisms either with white blood cells or proteins called antibodies. The immune system usually is able to mount an effective counterattack against invaders. The symptoms of an infection (such as fever, pain, and inflammation) are the results of this struggle.
Once infectious microbes enter your body, it takes time for them to multiply and cause symptoms. This period before symptoms develop is called the incubation period, which can vary from a few days to several months, depending on the particular disease-causing microbe. Doctors know the incubation periods for most common infectious diseases, making it possible to figure out when, where, and how a person acquired a particular infection.
After exposure to some kinds of organisms, the immune system is able to respond to future infections by those specific organisms and protect against them. Immunization is a way to induce this protective immune response without actually having the infection. Immunization can be active or passive. In active immunization, a person is given altered live or killed forms of a particular disease organism to trigger the same immune response that would occur from exposure to the actual organism. In passive immunization, a person is given injections of antibodies (infection-fighting proteins) produced by people who have recovered from an infection with a particular microbe. The antibodies are generally administered in a liquid derived from blood, called immunoglobulin.
Infections usually are limited to specific organs or tissues in which the infectious organisms are able to