Fire ( mild heat and heat )

Fire, caused by excess of yang qi, often occurs in summer, but may be seen in other seasons. Fire, mild heat and heat vary in degree. Of the three, fire is the most severe and mild heat the least severe, yet they all share similar characteristics. The terms of fire heat and mild - beat heat, therefore, are often used to describe their common features.

Fire is a yang pathogenic factor characterized by burning and upward direction. Clinical manifestations include high fever, restlessness, thirst, sweating, mouth and tongue ulcers, swollen and painful gums, headache and congestion of the eyes. Restlessness, insomnia, mania, emotional excitement and coma or delirium may occur if pathogenic fire disturbs the mind.

Pathogenic fire often consumes yin fluid. Burning pathogenic fire heat can consume yin fluid and force it to the exterior of the body, leading to insufficiency of body fluid. Clinically, apart from high fever, there may be thirst with desire to drink, dry lips and throat, constipation and deep - yellow scanty urine.

Invasion by fire stirs up wind and causes disturbance of blood. Excess of fire heat affects the Liver Meridian and deprives the tendons and meridian of nourishment, thus stirring up the liver wind. Clinical manifestations include high fever, coma, convulsion of the four limbs, neck rigidity, opisthotonus and upward staring of the eyes. These symptoms are known as " extreme heat stirring up wind. "

When pathogenic fire heat disturbs blood, it speeds up blood circulation and gives rise to very rapid pulse. In severe cases, blood is forced out of the vessels, leading to epistaxis, spitting of blood, bloody stool, haematuria, uterine bleeding and menorrhagia. Pathogenic heat may stay in and rot the blood and flesh, thus creating carbuncle, furuncle, boil and ulcer.