Fire is characterized by upward flaring.

Clinical manifestations are fever, thirst, profuse sweating, etc. If pathogenic fire travels inward to attack the mind, it causes irritability, anxiety, insomnia, or even mania, unconsciousness, and delirium in severe cases. Since pathogenic fire is likely to flare upward, the clinical manifestations may be mostly on the head and facial regions, such as a swelling and pain of the gums due to extreme stomach fire, ulcers of the tongue and mouth, headache, and redness, pain and swelling of the eyes.

Pathogenic fire is liable to consume yin fluid.

Manifestations are fever, aversion to heat, accompanied by thirst with desire for drinks (especially cold drinks), dryness of throat and mouth, constipation, yellowish urine, etc.

Pathogenic fire may disturb the blood and cause extravasation.

Mild cases will only have rapid pulse due to acceleration of blood circulation. In severe cases, the blood vessels and collaterals may be damaged, manifesting various hemorrhagic symptoms, such as vomiting of blood (hematemesis), nose bleeds (epistaxis), blood in the urine or stool, excessive menstrual flow, skin eruptions, external boils and ulcers, etc. The common syndrome caused by fire (heat) at the early stage is exterior-heat syndrome.

Main clinical manifestations: fever, mild aversion to cold, headache, sore throat, thirst, yellowish urine, dry stool, red tip and sides of the tongue, superficial and rapid pulse, etc. These symptoms are due to the invasion of fire (heat) on the body surface which consumes body fluids.

This concludes the discussion of the effect of the six exogenous pathological factors on the body. In general, these factors first damage the body surface and then manifest an exterior syndrome with the symptoms of fever and aversion to cold.