Elevation of body temperature above normal 36.8º (98.4º F).
A high body temperature, above the normal 98.6°F (37°C). Most infectious illnesses cause fever, which is a sign that the body’s temperature-regulating mechanism has been affected by the infection.
An elevation of body temperature above normal. Normal human body temperature is designated as 98.6° F or 37° C.
A rise in body temperature.
A condition when the temperature of the body is higher than usual.
An abnormally high body temperature, above the normal 98.6°F (37°C), generally due to infections caused by bacteria or viruses but sometimes stemming from other types of problems within the body, including reaction to medications. Fever is a natural part of the body’s reaction to invasion by disease organisms, but it can have serious effects, especially in young children. Most serious, very high fever can cause convulsions, coma, and even death in some situations. Other common accompanying symptoms are confusion; delirium; shivering; headache; thirst; flushed, hot skin; rapid breathing; and alternating shivering and sweating.
Rise in the temperature of the body. Normal body temperature is 98.6° Falnenheit (37.0° Celsius) taken orally, somewhat higher rectally. A rise in temperature can sometimes be caused by severe stress, strenuous exercise, or dehydration, but fever is most often a sign of infection (bacterial, viral, or other) or other disease. Fever is often accompanied by headache, chills, and feeling of malaise; high fevers can cause delirium and convulsions (especially in young children). The onset, course, and duration of a fever vary with the cause; certain diseases are associated with characteristic rising and falling curves that may aid in diagnosis. Also called pyrexia.
Body temperature above the normal range, which is an orally taken body temperature of 98.6°F to 100°? in adults aged 18 to 40. Fever in children is measured at higher values because children have a slightly higher normal body temperature. A child is diagnosed with a fever when he or she has a temperature above 100.4° F when measured rectally, 100°F when measured orally or in the ear, or 99° F when measured under the arm. The body temperature rises in response to an attack on the body’s immune system by agents such as bacteria or viruses.
A rise in body temperature above the normal, i.e. above an oral temperature of 98.6°F (37°C) or a rectal temperature of 99°F ( 37.2°C). Fever is generally accompanied by shivering, headache, nausea, constipation, or diarrhea. A rise in temperature above 105°F (40.5°C) may cause delirium and, in young children, convulsions too. Fevers are usually caused by bacterial or viral infections and can accompany any infectious illness, from the common cold to malaria. An intermittent fever is a periodic rise and fall in body temperature, often returning to normal during the day and reaching its peak at night, as in malaria. A remittent fever is one in which there is a daily diminution of the fever, as in typhoid fever.
Abnormal elevation of temperature. The normal temperature taken orally ranges from about 97.6° to 99.6°F, although there is individual variation. Rectal temperature is 0.5° to 1.0°F higher than oral temperature. Normal temperature fluctuates during the day and is lowest in the morning and highest in the late afternoon; these variations are maintained during a fever. The expended basal energy is estimated to be increased about 12% for each degree centigrade of fever.
Medically referred to as pyrexia, a fever is characterized by an elevation of body temperature above the normal level of 37°C in the mouth and 0.6°C lower in the axilla (armpit). Fever can come with various symptoms, such as shivering, sweating, a headache, thirst, unusually rapid breathing, and a flushed face. In some cases, confusion or delirium may also be experienced, particularly in elderly individuals. Young children, especially those under five years old, may experience seizures (febrile convulsions) or even fall into a coma if they have a high fever.
The majority of fevers arise from either bacterial infections, like tonsillitis, or viral infections, such as influenza. When these infections occur, the body’s white blood cells combat the invading microorganisms, leading to the release of proteins called pyrogens. These pyrogens then interact with the temperature-controlling center in the brain, prompting an increase in the body’s temperature. The purpose of this response is to aid in the eradication of the harmful microorganisms.
In addition to infections, fever can also manifest in various other conditions where there is no infection involved. These conditions encompass dehydration, thyrotoxicosis (a condition arising from excessive activity of the thyroid gland), lymphoma (a tumor affecting the lymphatic system), and myocardial infarction (commonly known as a heart attack). In these cases, the body’s temperature can increase as a response to these non-infectious factors.
Medications like aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or paracetamol can be administered to lower fevers caused by infections. However, when fever stems from other reasons, the focus of treatment shifts to addressing the root cause. For instance, bacterial infections are typically treated with antibiotic drugs, targeting the underlying issue rather than solely managing the fever symptoms.
An increase in the body’s typical temperature, which is around 98.6°F but can naturally reach up to 99°F in children and elderly people without indicating illness. Historically, the term “fever” was specifically associated with scarlet fever, a once-feared and severe condition. However, due to contemporary treatments, it is now considered relatively mild.