Chronic dry mouth may not be solely lack of salivation. Besides sympathetic inhibition of salivary glands causing hyposalivation, there is often underlying heat within the oral microcirculation and the whole organism. Natural herbal remedies for dry mouth can not only increase the flow of saliva, but also decrease the heat production that perpetuates xerostomia.
Xerostomia is the subjective sensation of oral dryness, which may or may not be associated with hyposalivation, defined as the flow of saliva < 0.1 ml/ minute.
According to many studies, the symptom of dry mouth and actual flow rate of saliva correlate poorly with each other. One study published in Journal of American dental Assoc. 2010 March 141 showed that out of 252 persons older than 70 years, 43 persons reported the symptom of significant dry mouth, but only 8 of them had hyposalivation by measurement. On the other hand, actual hyposalivation was found in 28 persons ( 11 % ) of whom only 8 persons reported the symptom of dry mouth. Why is there such a poor correlation between xerostomia and hyposalivation?
The flow of saliva is regulated by autonomic nervous system as well as local arteriolar vasodilation. With the activation of parasympathetic system, acetylcholine mediated salivary glands flow result in saliva with higher water content of 99.5%. The activation of sympathetic system results in norepinephrine induced, more thick salivas with more proteins. Norepinephrine also causes initial vasoconstriction, but local arteriolar vasodilation follows. Everyone knows that Heat is generated metabolically by all the organs and then carried to oral submucosa by blood. Now when more heat is produced chronically by the overworking organs and carried to oral submucosa, the local vasodilation must result to emit extra heat. When sympathetic tones to the salivary glands are strong, then this extra heat will dry up the saliva more into either thicker forms or even into scarcity. The extra heat in oral mucosa also appears as more red, dry tongue. Dry mouth in most cases are not simply due to hypofunction of salivary glands, except in cases of autoimmune dysfunction or damage by radiation or surgeries.
Trapped Heat which an organism cannot transfer to the environment on time is one fundamental imbalances of bioenergies. Chronic Dry mouth is one major manifestation of it.
Chronic Dry Mouth is often accompanied by other symptoms of heat inside our bodies. Such symptoms may include dry eyes, dry nose, dry cough, dry stools, feeling hot in general, hot tongue, hot flashes, hot palms and soles, hot ear lobes, easy sweating, night sweating, etc. Chronic dry mouth is often a symptom of disturbed homeostasis, and often a part of systemic disorder.
One initiating cause of disturbed homeostasis in internal temperature is the production of excess heat during " excessive " metabolic reactions. A common case is that of heat produced in brain during excessive mental exertions such as thinking or worrying too much. Chronic excess heat is also produced in liver with an overload of toxins/ drugs. Excess Heat can be produced by skeletal or cardiac muscles under exertion or by inflamed stomach or intestinal mucosa. Heat produced by biochemical reactions in diverse overloaded organs are carried by the blood vessels to oral mucosa, as well as cheeks, soles, and palms to be emitted to the environment by local arteriolar dilation. Thus the familiar symptoms of dry mouth, sore throat, burning tongue, as well as hot face, palms, and soles result.
According to biomedicine, there are only 3 major categories which cause clinically persistent dry mouth by decreased salivation via inhibition of cholinergic neurons or destruction of salivary glands: 1) radiation to the head and neck, 2) sjogren's syndrome which affects only the people with autoimmune disease with autoantibodies ( it is a rare cause of dry mouth especially in elderies ), and 3) medications, whose list number 500, practically all the drugs used medically, all purely on the basis of the listings of unwanted effects. Medications are overblamed ( dry mouth or xerostomia with hyposalivation can be caused by many drugs, with anticholinergic effects such as antihistamines, antidepressants, or codeines. However, whenever the causes for dry mouth cannot be found, medications or " polypharmacy " are routinely blamed and there are no convincing clinical evidences or known pharmaceutical mechanisms). The remaining cases of dry mouth which are a huge percentage are called Idiopathic.
Simplified explanation of dry mouth by eastern herbal theory:
The majority of people with xerostomia do not have decreased function of salivary glands. Often a sign of longstanding imbalance of "yin and yang ", chronic dry mouth ( some with red tongues with cracks ) is perpetuated by Heat, either full or deficient, reaching the root of mouth via the meridians( the channels where Qi and " Blood" flow). Squeezing the salivary glands only to produce saliva is like keeping pouring water into a hot cauldron with burning firewoods underneath. One can have chronic low grade fever internally generated which is not measurable by thermometer. To treat persistent chronic dry mouth, the burning firewoods must be cooled down slowly. ( The firewoods are often caused by " Yin deficiency of liver, kidney, lung, heart, spleen, or stomach with empty heat"; Yin is that aspect of bioenergy nourishing and moistening the organism ( salivation included ), while deficient heat is like friction heat produced when an engine is overrun.). Other common syndromes of chronic dry mouth include 1) heat/ fire in stomach or spleen, 2) heat or damp heat in liver or gallbladder often caused by liver/spleen disharmony, 3) blood stasis.
A few words about the herbs for chronic dry mouth. If one has much heat inside the body in different organs, the following saliva stimulant herbs ( " sialogues" ) should not be used. These hot herbs are Cayenne peppers, Ginger, Chinese Prickly Ash ( which are likely similar to Zanthoxylum clava-herculac or commonly used prickly ash ).