Here are some patterns of fever.
An Intermittent fever involves periodic occurrences of fever and normal or subnormal temperature.
Likewise, a remittent fever is characterized by more than two degrees of Fahrenheit temperature fluctuations between morning and evening that do not reach normal levels.
A constant or continuous fever is when the temperature remains high and fluctuates by less than 1.5 degrees Fahrenheit.
A Relapsing fever is characterized by recurrent episodes of fever where the body temperature normalizes for at least a day and relapses soon after.
An Inverse fever is when the body temperature peaks in the morning and decreases by evening.
A Lysis fever involves temperature fluctuation in a zig-zag pattern for a few days, sometimes up to a week, before returning to normal levels.
Similarly, a crisis fever occurs when the body temperature rapidly drops after prolonged high temperatures.
A crisis fever is categorized as true or false. In a true crisis, the patient's condition improves; in a false crisis, it does not.
Lastly, a fever of unknown origin lasts for weeks to months and has no apparent cause.