Too Few Urinations? Beware Hypertension and Stroke

Among patients I see, whenever I feel a wiry (xian) pulse, I often ask: Is your frequency of urination very low? Normally, how many times do you urinate in the morning and in the afternoon? Most wiry-pulse patients tell me they urinate only 0-3 times a day, often going an entire morning or afternoon without urinating. If you check the blood pressure of such patients, nine times out of ten it is too high or too low, or they have a family history of hypertension or hypotension. A wiry, forceful pulse usually means hypertension; a wiry, forceless pulse usually means hypotension—though not absolute, the probability is high.

The wiry pulse, as the name suggests, resembles a bowstring or a string on a musical instrument. The Suwen says: "The wiry pulse is straight and long." The Maijing describes it as "like a drawn bowstring." The Zhubing Yuanhou Lun describes it: "Pressing, it does not shift, taut as pressing a string of a qin or se." The Maijie describes it as "like a zither string." In Li Shizhen's Binhou Maixue, a seven-character poem describes the wiry pulse: "The wiry pulse, distant, straight and long; wood exuberance in the liver channel should injure the earth. Anger fills the chest and one often wants to shout; mists cloud the pupil and tears stream down."

In a normal person, the pulse rises and falls rhythmically; on the pulse picture it does not resemble a bowstring. If we perceive an arterial pulsation like a bowstring, the vessel wall is under abnormal pressure, so blood pressure is likely abnormal. The wiry pulse is highly distinctive and easy to distinguish from others. Those who often see stroke sequelae will remember this pulse vividly, because the vast majority of stroke-sequelae patients have a wiry pulse. Such patients are indeed irritable; TCM holds their liver fire is too exuberant, which is why Li Shizhen's verse says they "often want to shout"—this is grounded in fact.

In TCM, one of the most common diseases associated with the wiry pulse is phlegm-rheum disease. Zhang Zhongjing in the Jingui Yaolue already wrote: "A deep and wiry pulse indicates suspended rheum"; "The cough patient with a wiry pulse has water; Shizao Tang governs." Phlegm-rheum is a disease in which fluids linger in the body and cannot be normally excreted, so TCM treats it mostly with diuretics. Western antihypertensives also mostly have clear diuretic effects.

Most patients TCM calls phlegm-rheum patients have high blood pressure. High blood pressure is related to vascular aging, but more important is impaired excretion of body fluids. Fluids linger because the kidneys may be failing (causing renal hypertension) or because of excess antidiuretic hormone (ADH), also called vasopressin (VP), which raises blood pressure.

The body has both diuretic and antidiuretic hormones, which together regulate urine excretion into balance—not too much, not too little. A normal person should urinate about 10 times a day: 8-9 times by day and 1-2 at night—1-2 in the early morning, 3-4 in the late morning, and 3-4 in the afternoon. When ADH is too low, people easily have frequent urination, even polyuria severe enough to become diabetes insipidus. Frequent urination is not all bad: frequent urinators rarely have hypertension, which is why many live longer. When ADH is too high, urination becomes very sparse, and blood pressure rises along with it. Such people may have normal blood pressure when young because vessel walls are elastic, but by their thirties or forties, abnormal blood pressure appears.

ADH levels are closely related to genetics and greatly to lifestyle; most patients reflect the combined effect of heredity, environment, and habits. High-sodium and high-fat diets raise ADH, making such people prone to hypertension and obesity, and possibly progressing to kidney disease, diabetes, and cancer. They also have more fatty plaques in their vessels and are prone to diseases linked to hemiplegia or paralysis.

Thus, too few urinations is a warning sign worth heeding. If you find yourself urinating too rarely, and your paternal or maternal family has a history of hypertension or obesity, pay special attention to adjusting your lifestyle: eat low-fat, low-sodium food, keep regular hours, and eat more diuretic foods such as radish, bottle gourd, winter melon, pumpkin, corn, and coix seed.

It should also be noted that China currently defines adult blood pressure below 140 as normal. In fact, the latest research shows blood pressure is best below 120; anything above 120 carries stroke risk.