Diseases caused by endogenous heat are often marked by a low fever in the afternoon, a feeling of heat in the palms and soles, malar flush, night sweating, constipation, concentrated urine, reddened tongue with scanty or no coating, and thready rapid pulse. There are, apart from the above, some other pathological products that give rise to clinical syndromes, and so are regarded as pathogenic factors, or intermediate pathogenic factors. They are stagnated qi and blood, retained fluid, and accumulated phlegm. Stagnation of qi may produce a variety of syndromes marked by pain. Examples of this are irascibility when the qi is stagnated in the liver and constipation when qi is stagnated in the large intestine.
Blood stasis can also lead to further disorders as a pathogenic factor.
In Western medicine, blood stasis usua1ly refers to venous congestion, but in traditional Chinese medicine, it covers a large variety of pathological changes associated with retardation or stoppage of blood flow. Blood stasis is usually accompanied by pain, but this pain is different from that due to stagnation of qi. The former is generally severe, stabbing, and fixed in location. A purplish tongue or purple spots on the tongue is often seen in patients with blood stasis. Retention of excessive fluid is often the result of a dysfunctioning kidney, Spleen or lung.