A taiyang disease is a pathological syndromes caused by exogenous pathogenic factors invading the body surface; it is also known as an exterior syndrome. Taiyang disease can be classified into syndromes of the Taiyang channel and syndromes of the Taiyang fu organ (urinary bladder).

Syndromes of the Taiyang channel:
-- Aversion to cold, fever, pain and rigidity of the neck, thin white tongue coating, floating pulse.
-- Exogenous pathogenic factors attack the body surface injuring the defensive yang qi causing an aversion to cold. Fever is due to the obstruction of yang qi. Since the qi of the Taiyang channel is also affected, this results in headache, and neck pain and rigidity. A floating pulse indicates that pathological changes are exterior.

These are common manifestations of Taiyang exterior syndromes. On this basis, if they are accompanied by sweating, aversion to wind, floating and superficial pulse, they are known as wind stroke syndromes of Taiyang or exterior xu syndromes caused when the defensive qi is invaded by exogenous pathogenic wind. This leads to a disharmony between defensive and nutrient qi. If aversion to cold is not accompanied by sweating and a floating tense pulse, this is understood as Taiyang febrile syndrome caused by cold or exterior shi syndromes. In this case, exogenous pathogenic cold has obstructed the body surface and blocked the yang qi flow.

In addition, since the lung dominates the skin and hair, if exogenous pathogenic factors attack the body surface, lung qi will lead to dysfunction causing nasal obstruction, cough, asthma, etc.
-- The fu syndromes of Taiyang:
The Taiyang fu organ syndromes are mainly due to a progression of Taiyang channel syndromes which are not cured when they are on the exterior, and then are transmitted along the channel into the urinary bladder. Taiyang fu syndromes are classified into water retention and blood retention syndromes.

-- Water retention syndromes:
Fever, perspiration, irritability, thirst with or without preference for drinks, vomiting after drinking, and dysuria.

These syndromes are due to exogenous pathogenic factors being transmitted from the exterior to the interior, giving rise to qi activity dysfunctions in the urinary bladder. This further affects the body fluid flow leading to fluid retention and its sequence of irritability, thirst with preference for drinks, vomiting after drinking, and dysuria.
-- Blood retention syndromes:
Pain and lump in the lower lateral abdomen, mania, normal urination.

Pain and lump in the lower lateral abdomen resulting from pathological heat transmitted along the Taiyang channel and mixing with blood in the lower jiao. Mental mania is caused by an upward disturbance due to blood retention and pathogenic heat. Since the disease location is in the blood of the lower jiao, the urinary bladder is not affected, thus there is normal urination.