Low-grade fever

A low-grade fever is when a person's body temperature is slightly higher than normal range but not high enough to be qualify as a fever. A low-grade fever is often classified as an oral temperature that is above 98.6° F (37° C) but lower than 100.4° F (38° C) for a period of 24 hours.

Prevalence

 * In a 2001 Belgian study, 45.7% of patients meeting the Fukuda criteria and 56.5% of patients meeting the Holmes criteria, in a cohort of 2073 CFS patients, reported low-grade fever.

Symptom recognition

 * In the Holmes criteria, a mild fever (oral temperature between 37.5°C or 99.5°F and 38.6°C or 101.5°F, if measured by the patient) is an optional criteria for diagnosis, under the section Minor Symptom Criteria. It also appears as an optional criteria for diagnosis under the section Minor Physical Criteria as a low-grade fever (oral temperature between 37.6°C or 99.7°F and 38.6°C or 101.5°F, or rectal temperature between 37.8°C or 100°F and 38.8°C or 102°F) that has been documented by a physician on at least two occasions, at least one month apart.