What are the 5 Main Causes of Fever?
THOUSANDS of people each day slip thermometers under their tongues, wait a few minutes, then consult the little arrow. Most laymen believe that the higher the body temperature the graver the illness. Doctors aren’t so sure. For two thousand years, medical men have been debating the question: is fever friend or foe? Is it an indicator of how ill a person is-or of how vigorous an effort his body is making to get well?
What is fever?
It is simply an indication that the body is generating heat faster than it is losing it. Your body’s remarkable heating system is in many respects strikingly like a home heating system. The food you eat is burnt, mainly in muscle tissue. The resultant heat is piped round the body by the blood in blood vessels.
Like a well-built home, the body has its insulation—a layer of fat under the skin-to cut down heat loss. The entire system is controlled by cells in the hypothalamus, on the under- side of the brain. This is the body thermostat. When it is pushed too high, there is fever. The sweating mechanism slows down and the skin becomes dry and hot.
No real studies of body temperature were made until, in the middle of the last century, Dr Carl Wunderlich of the University of Leipzig measured temperatures of 100,000 people and concluded that “normal” body temperature was 98.6° Fahrenheit.
Today’s research men note that body temperature varies widely during the day-being lowest in the early-morning hours, highest in the late afternoon. Therefore, doctors think it would be better to speak of a normal “zone”-from 97.2° to 99.5°.
Human Body Temperature and What are the 5 Main Causes of Fever?
Although the blood is highly efficient as a distributor of heat, it doesn’t do a perfect job. If the mouth temperature is 98.4°, the rectal temperature is usually a degree higher. The liver, hottest organ in the body, it is about 101°. The groin area is usually at least a degree lower than the interior of the body. Survival of the human race depends on its rising no higher. Above this level, male reproductive glands are unable to produce sperm.
What induces fever?
A surprising variety of causes. Anxiety is one. Children frightened by going to the hospital often run fevers in the 101° to 103° range. One army doctor found that the temperatures of 324 call-up examinees, anxious about their status, averaged nearly a degree above normal. Also, injury to the brain thermostat-caused by accidents or by tumours growing into the area-often produces raging fevers.
By far the largest producers of fever are bacterial and viral diseases. The exact means by which these microbes cause fever is not known. It may be that under microbial attack white blood cells release fever-producing chemicals called pyrogens which prod the brain thermostat into action.
Are fevers harmful?
There is no cut-and-dried answer. Some fevers are clearly dangerous-particularly those caused by brain injury, tumours, sunstroke. They soar to levels where temperature itself becomes a menace to life. A fever of 109°, for example, does irreparable damage to the brain if not brought under quick control by ice-water enemas or immersion in baths of ice water.
Fevers following heart attacks are also grave affairs. The danger here is this: in fever the rate of cellular activity in the body (metabolism) may be greatly increased. At this faster rate the cells require more oxygen. Thus there is an added load on an already damaged heart.
These are the exceptional cases. About the more common fevers that accompany colds, sore throats and such, one point should be remembered: fever is not a disease but a symptom-often a valuable and revealing one. Many doctors are today question- ing the wisdom of fighting common fevers with temperature- reducing drugs—such as aspirin.
Speaking mainly of childhood diseases, one professor of medicine observes: “Anti-fever therapy is often employed more for the benefit of parents, or the doctor, than the child. It is doubtful whether body temperatures in the range of 104° are harmful, even if prolonged for several days.”
Fever may be the best, or the only, available sign for following the course of an illness, as many diseases have readily recognized temperature patterns. In typhus, for example, fever is continuous. Malaria has a relapsing pattern-normal for a few days, followed by an upward swing. In typhoid there is a remittent pattern (marked fluctuations remaining above normal); in bone infections and abdominal abscesses there is an intermittent fever (where normal is approached at some time during the day).
What are safe limits for fever?
There is no hard and fast rule. It has been observed that people rarely survive temperatures above 109°. However, temperatures almost never rise above 106°. Apparently, the body has some emergency mechanism that takes over at this point. A chain of life-saving events gets under way. The patient usually goes into a coma, blood flow to the blood vessels near the surface of the body is increased and sweating becomes profuse. These events produce a cooling effect, and the fever begins to fall to safer levels.
Fearsome as fever may be to laymen, it has many beneficial effects. It prods the body into greater production of bacteria- fighting white blood cells and bacteria-killing antibodies. Recent evidence indicates that it increases production of the hormone ACTH, which in turn combats the stress placed on the body by disease. It appears to enhance the action of such antibiotics as penicillin.
At certain reasonably safe temperature levels some bacteria are simply cooked to death. Last century, for example, doctors noted that after bouts with certain feverish diseases (malaria, typhus) many patients were cured of syphilis. This led Dr. Julius Wagner- Jauregg, an Austrian doctor, to infect patients with malaria as a treatment for syphilis, and led later on to production of artificial fevers with high-frequency electric current.
As wider knowledge of fever has accumulated, many old rules have been rewritten. A generation ago it was standard practice to “starve a fever”-which undoubtedly killed many badly debilitated patients. Since fever hoists the metabolic rate, the need for food and fluids is increased. Today’s rule: a high-protein, high-vitamin diet, with all the liquid the patient can take.
Another old rule was to cover the feverish patient with blankets and heat up the sickroom-so that he could “sweat it out.” This was the worst possible treatment. In fever, the body is struggling to get rid of heat. Why make the job more difficult? Today’s rule: a comfortably coldish room, light bed covering.
Until recently it has been customary to keep feverish patients in bed. Under certain circumstances this rule, too, may be ready for discard. One doctor collected records of 1082 feverish youngsters. Some were confined to bed, some were allowed up and about the home.
Temperatures returned to normal at almost exactly the same rate with each group. The doctor concluded: “This study seems to indicate that in ‘ordinary’ or ‘self-limiting’ illnesses. children may rest as they desire, and play quietly in the house.” To sum up: Fever is no longer the frightening thing it once was. According to present-day thinking, the great majority of fevers are more apt to be friends than foes.
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