"Craniocerebral retention of fluid" refers to blockage of craniocerebral blood stasis and phlegm dampness in the brain. There were such accounts in ancient medical books. In《Exposition on Regulation of Meridians. In: Plain Questions》, there is such an account: "If there is water overflowing in minute collaterals, the meridians will have retained blood."《Synopsis of Prescriptions of the Golden Chamber》says: "Failure in blood circulation in the vessels leads to escape of water." In《Treatise on Blood Diseases》, there are such accounts: " Pathogenic blood is not without pathogenic water and pathogenic water is not without pathogenic blood," and "With prolonged accumulation of extravasated blood, water follows." In clinical practice, the use of activating blood circulation and diuresis to treat many refractory brain diseases such as infantile metopism (hydrocephalus), senile dementia, apoplexy, cerebroma and post-traumatic brain syndrome can get twice the result with half the effort. We hold that the advancement of the theory of craniocerebral retention of fluid has ample theoretical basis and that the formation of the theory is of important practical value to treatment of encephalopathy.
Water and Blood Have a Common Source and There are Interdependence and Interosmosis Between Water and Blood.
Both blood and water are transformed from the essence of food and produced in the spleen and stomach. Relying on qi as their motivating force, they circulate in channels

Author's unit: Guangdong Gaoming Medical and Medicinal Institute of Encephalopathy, Gaoming, Guangdong 528500.
and vessels to nourish the entire body. Blood and water are the essential substances of vital activity. Water is a substance of blood, the transformation of blood needs participation of water, blood without refined nutritious substances is water. Therefore, water and blood are mutually useful and interdependent.
Blood circulates in vessels and channels and cannot overflow outside the vessels and channels, and the running of water relies on osmosis inside and outside the vessels and channels. With osmosis inside the channels and vessels, water is a component of blood; with the refined nutritious substances osmosed outside the channels and vessels, blood becomes body fluid. Therefore, the water in blood and the refined nutritious substances run all over the body by means of the mode of osmosis inside and outside the channels and vessels to nourish viscera, muscles, the five sense organs and nine orifices, thus the mutual osmosis inside and outside the channels and vessels is the basic mode of mutual use between water and blood and also the physiological foundation of the theory of "craniocerebral retention of fluid."
If water is Affected With Illness, Blood Will be Involved; It's the Same the Other Way Round. Physiologically, blood and water have interpromoting and interosmotic relation, they are necessarily closely related in pathology. In《Treatise on the Development of Diseases. In: Classic of Miraculous Pivot》, there is such an account: "Retention of damp-qi leads to stagnation of blood and uneven osmosis of body fluid with the result that accumulation follows."《Treatise on Blood Diseases》also points out: "With blood affected, water is also involved." These inferences all show from the angle of clinic the pathological changes of blood blocking and water retention, and water stagnation and blood stasis.
The brain controls mental activities, water and blood are the material basis of the brain. The brain is also known as the sea of marrow and the house of mental activity, it is nourished by qi, blood and body fluids, and the running and transportation of qi, blood and body fluids is regulated by the brain. Disturbance in transportation of body fluids or sluggishness of blood circulation will necessarily lead to osmotic abnormality of craniocerebral body fluids. Blood stasis in vessels and channels and obstructed water running make the osmosis outside the vessels and channels enhanced with water retention outside the vessels and channels, and the water outside the vessels and channels again constricts vessels and channels and exacerbates obstructed circulation of blood, with water retention in the body or in a local part.
Disease due to retention of fluid may be found in the whole body or in a certain tissue of local part. This also widens the scope of use of the theory of fluid retention.
Craniocerebral Retention of Fluid is the Key to Encephalopathy. The brain is the extremely lucid visceral organ and cannot be invaded by pathogenic factor. With invasion by pathogenic factor, the brain will fall ill. Craniocerebral retention of fluid is etiologically complex and is commonly found in deficiency of the kidney-essence and loss of nourishment of the seven orifices, and in the presence of dysfunction of the liver in dispersion and discharge, disorder of qi, or dysfunction of the spleen in transport, and retention of dampness in the interior, then stagnation of qi, blood stasis and retention of water develop; or in the presence of craniocerebral injury due to injuries from falls, fractures, contusions and strains, then stagnation of qi and blood and water intermingled with blood follow. In short, the pathogenesis of various encephalic diseases is obstructed flow of qi and blood, which causes blood stasis of cerebral vessels and channels or hemorrhage due to collateral rupture, resulting in accumulation of blood stasis, outward osmosis of fluid, water intermingled with blood, loss of nourishment of the brain and a variety of deteriorated cases. The characteristic manifestations are mental derangement, dysfunction of extremities and the nine orifices, unconsciousness, sluggishness, retardation in reaction, insomnia, amnesia, numbness of limbs, swelling, weakness, tremor of hands and feet or hemiplegia, aphasis, wry mouth with distorted eyes, tinnitus and deafness, or even urinary and fecal incontinence, and macrocephaly, infantile metopism, exposed facial blue veins and inferior view of both eyes in infants. Patients with craniocerebral retention of fluid have purplish red tongue or purplish tongue, tongue with ecchymosis, thick teeth-printed tongue and deep, thready and uneven pulse.
The Brain is Valued for its Unobstruction, Promoting Blood Circulation Should Combine With Diuresis. The brain is valued for its clearness and unobstruction, so treatment should be based on restoring consciousness and clearing the cerebral passage and on activating blood circulation and using diuretic to alleviate water retention. In the diagnosis and treatment of craniocerebral retention of fluid, removing blood stasis alone cannot eliminate water, diuresis alone cannot remove blood stasis, only removing blood stasis in combination with diuresis can take effect. Clinically, supplementing qi, tonifying the kidney, warming yang and enriching the blood can be given as one sees fit, and this can take the effect of complementing each other. Such drugs used both to activate blood flow and to alleviate water retention as cyathula root, cogongrass rhizome, poria, motherwort and oriental waterplantain rhizome are commonly used in clinical practice. They can bring about a clearance of cerebral passage in the upper part and ensure proper downward flow of the blood to make free circulation of the blood by removing blood stasis and water retention.