Dryness is related to the season of autumn and to the Lungs. External Dryness characterized by dehydration can be caused by either Heat or internally by Deficiency of Blood or Yin. Dryness caused by dehydration and Heat causes hot feelings and a flushed, red appearance. Warm-Dryness usually occurs in the heat of late summer and early Autumn. Cool-Dryness usually occurs during late Autumn with the onset of pathogenic Cold of approaching Winter. Dryness is a Yang phenomenon.
Dryness usually invades through the mouth and nose, afflicting the Defensive Qi and the Lungs. If the Lungs, considered a sensitive Organ, are lacking sufficient Yin moisture, they become vulnerable to the attack of Dryness. When this occurs, there may be Dryness of the mouth, nose and throat, dry cough with little Phlegm, asthma and chest discomfort. When Dryness invades it impairs Body Fluids, causing Dryness in the mouth, nose and throat with thirst, dry skin and constipation.
Dryness can also arise internally. This is usually caused by a Deficiency of Blood or Yin or the exhaustion of Essence. Excessive consumption of spicy, hot-natured foods, over-exposure to dry weather, and not drinking enough fluid can also lead to Dryness.
Internal causes of Dryness include the excessive consumption of drying foods (such as spicy, hot-natured foods), irregular eating, which weakens Stomach Yin, excessive use of the voice (e.g. teachers), which weakens Lungs Yin, excessive sexual activity in men, which weakens Kidneys Yin and Essence, chronic menorrhagia in women, which damages Blood as well as Liver and Kidneys Yin and smoking, which injures Lungs and Kidneys Yin.
The main symptoms of Interior Dryness are the same as for Exterior Dryness: dry cough, dry mouth, dry throat, dry nose, dry tongue and a Floating pulse.
The Stomach is the origin of Body Fluids and if one has an irregular diet, such as eating late at night, eating in a hurry or going back to work straight after eating, the Stomach Fluids are depleted and this leads to a state of Dryness, which is the precursor of Yin Deficiency.
The main symptoms of Stomach Dryness are a dry mouth, dry tongue and cracks on the tongue.
The Lungs like to be kept moist (from the ‘vapour’ arising from the Kidneys) and dislike Dryness. Excessive use of the voice over many years can cause Dryness in the Lungs, which can be the precursor of Lung Qi Deficiency.
The main clinical manifestations of Lung Dryness are a dry mouth and throat, dry cough, dry tongue, dry skin and a hoarse voice. Due to the relationship with the Large Intestine, Dryness of the Lungs in severe cases can cause dry stools.
The Kidneys especially loathe Dryness as it is the Organ ruling water metabolism. Kidneys Dryness can arise from excessive sexual activity in men, chronic menorrhagia (menstrual periods with abnormally heavy or prolonged bleeding) in women or from smoking.
The main symptoms of Kidney Dryness are a dry throat with desire to sip water at night, scanty urination, dry tongue with cracks, dry menstrual blood in women and dry skin.
External Dryness arises from invasion of Exterior Wind Dryness. This occurs when the person suffers an invasion of Wind either in very dry climates or when he or she is exposed to artificial, very dry working conditions.
As this is an invasion of external Wind, there is aversion to cold and a fever. Other symptoms are a dry cough, dry mouth, dry throat, dry nose, dry tongue and a Floating pulse.