The human urinary system consists of two kidneys, two ureters, a common urinary bladder, and a urethra.  The overall function of the urinary system is to maintain the well-functioning of the body by filtering metabolic wastes and excess electrolytes from the blood and to excrete them, along with excess water, as urine (meme raglayim (Machshirim 6:5)). The kidneys are bean-shaped filtering organs that produce highly concentrated urine (i.e., much metabolic waste in a small amount of water) that is passed through thin-walled tubes, the ureters, to a common holding sac, the urinary bladder. Urine fills the urinary bladder, a muscular wall that can expand to collect and store the urine. When the urinary bladder fills and stretches, the individual feels a sensation to urinate. A person is trained to voluntarily empty the bladder with the assistance of the cerebrum, which controls the tendency for the full bladder to contract and void its contents. The expulsion of urine is controlled by sphincter muscles at the junction of the bladder and the urethra; these muscles function as gatekeepers and are adapted to control the expulsion of urine from the bladder. When the bladder contracts, urine travels through the urethra to exit from the body. The only difference between the male and female urinary system is the urethra. In human males, the urethra transverses the male sex organ, transports both urine and semen, and is 18 to 20 cm in length.  In human females, the urethra is independent of the reproductive system, transports only urine, and is about 4.8 to 5.1 cm in length (1, 2).  

The Talmud places great stress of health hazards from withholding urination. Forcibly withholding urination results in jaundice (Bechoros 44b; Berachos, 25a, 62b; Tamid 27b), extension of the abdomen (Bechoros 44b), and sterility (Bechoros, 44b; Yevamos 64b), and causes the individual to transgress the biblical commandment (Yayikra 20:25), “Do not make yourselves abominable” (Makkos 16b). The Talmud relates several incidents in which the need to urinate overrode the practice of modesty.  When reading these incidents it is important to remember that society was different, urination was simply viewed as a necessary bodily function, many people lived in agricultural communities in which the outdoor lavatory simply was a portion of a field, and those living in cities were without indoor plumbing. Homes had a urine basin (or, chamber pot) that was used by both male and female household members (Niddah 59a).  An incident involved Rav Ashi, who needed to urinate while standing on the plank of a bridge. When informed that his mother-in-law was approaching, he replied that it was better to urinate and thereby avoid health issues than to withhold his strong urge to urinate (Bechoros 64b). Another incident is described with Shmuel, who needed to urinate while presenting a public discourse on a Shabbos during the 30-day period preceding a festival.  To provide some privacy, Shmuel’s colleagues spread a cloak between him and the audience, thereby allowing him privacy. When this incident was told to Shmuel’s father, he angered, as Shmuel had set a new precedent of requiring a person to withhold urination and to wait for a modest setting to urinate. Now, the average person, without colleagues willing to spread a cloak for his modesty, would withhold urination and thereby risk sterility (Bechoros 44b). A story is told of Rav Huna, who presented extremely long lectures. His students, which included Rav Gidal, Rav Chelbo and Rav Sheishess, were so engrossed in his lectures that they withheld urination and became sterile.  Rav Acher ben Yaakov was at these lectures, but upon their conclusion, he immediately left the shiur to urinate and thereby he avoided sterility (Yevamos 64b). Another story involves Rav Yehudah and Shmuel who were standing on the roof of a synagogue. Rav Yehudah needed to urinate and was advised by Shmuel not to urinate on the synagogue roof, as the prayers of those inside the synagogue travel upward. Rather, Rav Yehudah was instructed to go to the edge of the synagogue roof and to urinate outward, away from the roof (Niddah 13a) (see note #35 of the Artscroll edition).

If a woman is with her child and she needed to urinate, she should not urinate directly in front of the child but rather should stand to the side and urinate (Bechoros 44b). Abaye advised the Rabbis that when passing through the city to go out to the fields to relieve themselves, “do not gaze to either this side or to that side, for perhaps women will be sitting there relieving themselves and it is not proper to gaze upon them” (Berachos 62b). Regarding urination, the standards of modesty have changed drastically from Talmudic times (when indoor plumbing did not exist) to current times. Rav Moshe Feinstein noted that it is permissible for a male to urinate in a public restroom in which there are many urinals in one common room. Yet, if possible, for modesty, the male should urinate into lavatory bowl within a partitioned stall (Igros Moshe, Yoreh Deah III: 4715, cited in the Artscroll edition of Tamid, 27b, see note #39).   

In the era of the Talmud, men were accustomed to urinating on the walls of buildings. The Talmud advises to avoid urinating against a wall made of clay bricks, which dissolve by the urine. If the wall is of stone, which is impervious to urine, the male should distance himself a tefach (a length equal to the width of four thumbs) from the wall, lest the urine will soften the ground adjacent to the base of the wall, possibly leading to wall collapse (Bava Basra 19b).  Male urination against walls is still in vogue. Public urination in San Francisco has become so prevalent that the city painted walls of buildings with a repellant paint that makes the urine splash back upon the shoes and pants of the urinating males. The issue was prompted when a light pole that was corroded by urine fell upon a car (3).

Urine voiding begins when a voluntary nerve signal is sent from the cerebrum to begin urination which continues until the bladder is empty. Human male urinate either standing or sitting. Towards the end of the voiding process, residual urine remaining in the urethra is expelled by contractions of the  bulbospongiosus muscle in the male organ (4).  As noted in Talmud Berachos (40a), urine does not empty completely from the urinary bladder unless one urinates while sitting. This has many implications. As explained in the Artscroll edition of Berachos (40a, see note #16), when a male stands while urinating, the forceful stream of urine eventually weakens and the urine lands closer to the person. The individual may prematurely arrest the flow, perhaps causing droplets of urine to hit the nearby ground and bounce onto his feet. The issue with urine droplets on his feet may lead to gossip, with people assuming that these droplets resulted because this male had a severed male organ, causing the urine stream not to arch away from the body, but to dribble. Subsequently, this cast doubt on his capability of fathering children, suggesting that perhaps his children were not fathered by him and were mamzarim (Niddah 13a). To prevent this suspicion, a male must wipe urine droplets on his feet (Yoma 30a).  This suspicion was based on the knowledge that a eunuch’s urinary stream does not form an arch (Yevamos 80a) and is not strong (Yevamos 80b). However, when a male urinated while sitting, rather than standing, the bladder empties more completely and urine droplets bouncing from the ground onto his feet were not an issue (Berachos 40a).  For kohanim working in the Beis HaMikdash and needing to urinate, the potential of urine droplets on their feet required anyone who urinated to wash his hands and feet with water from the kiyor (laver) (Yoma 29b).  

According to the Talmud, the main health concern of withholding urine is that it may lead to male sterility. An extensive literature search on PudMed did not yield published research in scientific peer-reviewed journals that connect sterility to withholding urination.  In fact, the phrase “withhholding urination and health hazard” yielded no hits. Apparently, science is lagging behind the Talmud. The physiological effects of withholding urination have not, as yet, been studied by the scientific community.

It has long been assumed that nonpathogenic microbes existed only in the lower portion of the urethra and that the urinary bladder was a sterile environment (5). Thus, clinical urine specimens usually are considered to be sterile when they do not yield uropathogens using standard clinical microbiological procedures. However only 3 years ago it was shown that the adult bladder is not sterile, but there are indigenous nonpathogenic bacterial populations that previously were not identified by routine culturing procedures (6). The effect of withholding urination on these hither-to-for unknown microbial populations in the bladder is unknown.  As urination flushes bacteria out of the urethra, withholding urination possibly would promote growth of these indigenous bacterial populations, both in the bladder and in the urethra, as well as enhance the precipitation of crystals and urinary stones.

A male who experienced a seminal emission is considered tamei. To become tahor, he must immerse in a mikveh and wait until nightfall (Yayikra 15:16).  As semen and urine travel through a common tube, i.e., the urethra, urination cleanses any residual sperm resulting from a prior seminal emission (Niddah 42).  So, if a male who had a seminal emission immersed into a mikveh without prior urination, it is possible that traces of residual sperm remain in the urethra. If so, urination subsequent to immersion in the mikveh might result in expulsion of residual sperm, thereby making him tamei once again (Rashi on Chullin 24b).  As an aside, the Talmud (Bechorus 44b; Yevamos 75b, 76a) suggests that in the male organ, the urethra and the seminal tube are distinct structures, separated by a paper thin membrane, which is not the reality of today. To account for this discrepancy the Chazon Ish noted that since Talmudic times “nature has changed” and nowadays, both urine and semen exit the body through a common tube (Artscroll edition of Yevamos, 75b, see note #41)

The issue regarding male urination focuses on urine droplets on one’s feet and the resultant gossip that is generated. Regarding female urination, the focus centers on whether the woman noted blood in the urine and, if so, to identify the origin of the blood, whether from the urinary tract or from the genital tract. Chapter 9 in Talmud Niddah (59b) begins with a Mishnah presenting the following case: A woman who was attending to her needs (i.e., who urinated into a chamber pot) and saw blood in the urine. The question posed was whether the blood in the urine was from her uterus or from a wound in her urinary tract.  If the blood is from the uterus, then she is tamei, but if the blood was from her urinary tract, then she is tahor.

In a woman, after passing through the urethra, urine normally flows directly out of the body; it does not enter the vaginal canal and proceed upwards towards the uterus. If so, physiologically, how is it possible for urine from a female to contain uterine blood?  This question is tackled in the Artscroll edition of Niddah 59a, see note #7.  As background, it is important to note that in the female, while urine exists through the urethra and uterine blood through the vaginal canal, both orifices are surrounded and protected by the labia (4). Suppose, the woman constricted her labia, thus trapping within her body any urine that flowed out of the urethra. Without a mode of exit, the urine collected behind the labia and as more urine flowed from the bladder and accumulated, it eventually moved up the vaginal canal into the uterus.  Subsequently, upon urination, the urine contained uterine blood. [This brief discussion does not do justice to this topic and the reader is directed to the Artscroll edition of Talmud Niddah 59b for greater detail]. If blood in urine was detected intermenstrually, then it originated from a wound in the urinary system.  On this topic, in Nishmat Avraham, Dr. Abraham (7) cited siman 191 of the Shulcan Aruch, “If a woman passed blood while urinating, she remains ritually clean (tahor), whether she did so standing or sitting. Even if she had a hargashah (a feeling of flow), she need not worry since it is due to her urine. Urine does not come from the uterus and the blood is from a makhah (a wound) in the bladder or kidney.” Dr. Steinberg further noted that, “Nowadays, the differential diagnosis between genital and urinary sources [of blood] is relatively easy. Microscopic hematuria [the presence of red blood cells in urine] intermenstrually is strongly suggestive that the blood is coming from the urinary tract.”

Problems in urination are mentioned in the Talmud. Rav Yehudah HaNasi suffered from tzemirtha (bladder calculi (stones)) which impeded flow in the urinary tract and caused an excruciating pain (Bava Metzia 85a; Gittin 69b). Remedies to remove blockage of the urinary tract and resume urine flow included insertion into the urethra drops of tar oil, of leek extract, and of clear wine or a louse (Gittin 69b).  Rav Acher ben Yaakov withheld urination and developed sus’kinsa (Yevamos 64b; Rashi: strangury, which is defined as the distressing desire to fully void despite its impossibility, attributed to the irritation of the epithelium lining the urinary tract and subsequent muscle spasm). Withholding the urge to urinate may harm the urinary system causing urine to dribble, rather than to stream, from the person (Rashi, Bechoros 44b).

The sanctity of Eretz Yisrael is noted in the following recommendation: A person living in Babylonia should not urinate into an earthenware chamber pot nor onto non-absorbent hard soil, as eventually such urine will contaminate Eretz Yisrael. The contents of a chamber pot usually are tossed into any nearby river and wastewater from non-absorbent soil eventually will wash into a river.  These minor rivers eventually merge into the Euphrates River which, via underground channels, carries the urine to springs in Ein Eitam in Eretz Yisrael (Bechoros 44b).

Urea (CO(NH2)2), a waste product in urine, is degraded by microbes to ammonia (NH3), a caustic, but weak, base. The high pH of ammonia makes it a useful cleanser, as it neutralizes dirt, grease, and organic matter, which are slightly acidic.  Ancient societies used urine as an agent in softening and tanning of animal hides, as soaking animal skins in urine made it easier for the leather processors to remove animal hairs and pieces of flesh from the hides. Launders used fermented urine to clean clothes (8).  In Talmudic times, urine, left to sit for 3 days (Niddah 63a) until it became pungent, was used to cleanse garments stained with menstrual (niddah) blood (Niddah 61b, 62a; Shabbos 89b) and with chatas blood (Zevachim 95a). Because of the principle that undiluted urine was not brought into the Beis HaMikdash, kafrisin wine, instead of pure urine, was used to soak the onycha, a type of spice of the kotores, so as to make it more pungent (Kereisos 6a). 

The medicinal properties of urine are discussed in the Talmud. Forty-day old human urine (or, according to Rashi, urine of a 40 day old child) was applied to heal a wasp sting (Shabbos 109b). The drinking of donkey urine was an effective cure for jaundice (Bechoros 7b). Mention is made that some people drink human urine, believing it has curative properties (Shabbos 100a). As strange as it seems, urine therapy, or the drinking one’s own urine, is very popular in several countries. In China over 3 million people drink their urine and in Germany nearly 5 million people regularly drink their urine (9).  The consumption of urine, urophagia, was a means of survival for people in dire straits, e.g., those ship wrecked or those stranded upon a mountain (10).

“The kidneys counsel” (Berachos 61a), as derived from the verse (Tehillim 16:7, translated according to Rashi), “I will bless HaShem who counsels me, even by night my kidneys admonish me.”  What counsel do the kidneys provide and to whom is it directed?  Perhaps, this is an allusion that the kidneys counsel a physician regarding the health status of a patient, through the vehicle of a chemical analysis of patient urine.  Rambam, a physician, understood this concept and, in fact, authored a treatise on the analysis of urine.  In chapter 5 of Medical Aphorisms of Moses Maimonides,” he wrote, “It is obligatory to perform tests and to examine the urine every day during any fever, because fevers are sicknesses occurring in vessels.”  He noted that the physician should pay attention to the color of urine, evidence of precipitation and sediments within the urine, the consistency of urine, and the frequency of urination by the patient. In addition, he described the use of catheters, or tubes, to collect urine from a patient (11).       

“Urine has a unique valuable role in medicine: it holds clues not just to what people eat and drink, but also to how well their bodies are functioning. The search for these telltale signs is why doctors routinely request urine samples from patients, whether they seem healthy or are obviously sick” (12).  Below is a brief idea of the counsel that kidneys, via urine and a subsequent urinalysis, provide the physician regarding the patient. A urinalysis provides information on the following: (a) sodium ion - the level ascertains full kidney function; (b) potassium ion - decreased levels may reflect adrenal insufficiency and  hypoaldosteronism; (c) calcium ion -  the concentration provides information on  parathyroid disease and familial hypocalciuric hypercalcemia and elevated levels are predictive of the formation calculi (kidney and bladder stones); (d) phosphate ion - a low level is indicative of kidney dysfunction and an elevated level of hyperparathyroidism;  (e) nitrite ion - its presence is indicative of contamination by coliform bacteria; (f) protein - indicative of kidney dysfunction, possibly caused by hypertension, diabetes mellitus, and hyperthyroidism; (g) glucose - elevated levels are seen in patients with type 2 diabetes; (h) human chorionic gonadotropin - in females, it is indicates pregnancy, in males, it is indicates testicular cancer; (i) red blood cells - the occurrence may indicate a urinary tract problem (trauma, stones, microbial infection, cancer); (j) white blood cells - indicate pus and urinary tract infection; (k) ketone bodies - suggestive of problems in fatty acid metabolism; (l) bilirubin - the elevated level may indicate an increased rate of red blood cell destruction, liver damage, and obstruction of the common bile duct;  (m) free cortisol - levels below threshold indicate Addison’s disease and those above threshold indicate Cushing’s syndrome; (n) phenylalanine - important in neonatal screening to detect phenylketonuria;  (o) bacteria - above a threshold of 100,000 colony forming units/ml is indicative of bacteriuria (13) .  In addition, the color, clarity, and other physical characteristics of urine provide important medical information.  A sweet odor from urine may indicate diabetes mellitus; dark urine with an ammonia smell may reflect excessive sweating, drinking too little, or repeated diarrhea or vomiting.  Repeated excretion of dark-colored urine is characteristic of hepatitis. Blood in urine may appear as a result of a trauma to the kidneys, bladder, or urethra, of urinary tract infection, of a kidney or bladder stone, of an enlarged prostate gland, or of a malignancy. Constantly voiding foamy urine is a sign of protein excretion and a symptom of kidney disease, while voiding cloudy urine is suggestive of a bladder or urinary tract infection (12). 

Biotechnology and modern medical protocols have triggered novel halachos not applicable in prior generations, but based on established halachic principles from Talmudic times.  Below are a few of such modern halachos as relevant to urine or urination.

·  The bracha of Asher Yatzar is recited to thank Hashem for the ability to relieve oneself of metabolic wastes. Recitation of this blessing also is required when one gives a sample of urine for urinalysis (7).    

·  A person with a urinary catheter is required to recite Asher Yatzar to thank HaShem for allowing the catheter to function properly, as, at times, the catheter may become clogged. The time to recite the blessing is dependent on the type of catheter. If the catheter has a stopcock valve and the patient can control the flow of urine, then the bracha should be recited each time that urine is voided. If the catheter is attached to a urinary bag and there is a constant flow of urine into the bag, then the patient should recite the bracha once, together with the other morning blessings. The patient should have in mind to exempt himself from reciting the bracha the rest of the day.  A modification is that it is preferable for such a patient to wait until the flow of urine has stopped and only then should recite the bracha (7).   

·  In Talmudic times, when indoors, people used a wooden or clay basin as a urinal. These basins absorbed urine and often emitted a foul odor, even when cleaned; thus, reciting a davar shebikdushah in the presence of such basins was prohibited. Today, urinals are made of plastic, which have little absorptive capacity. If a plastic urinal was cleaned, both within and without, and did not emit a foul odor, a patient would be permitted to recite a davar shebikdushah in the presence of a thoroughly cleaned plastic urinal (7, 14).    

·  A dipstick allows for urinalysis to be performed at home. The dipstick is impregnated with chemicals that react with specific substances in the urine, to produce color-coded visual changes. The extent of the color produced, reflects the concentration in the urine of the specific substance of concern (15).  Dipsticks are available to measure urine levels of glucose (of concern to diabetics) and of luteinizing hormone (of importance to women in need of assisted reproduction technologies) (16). Whereas coloring or dyeing on Shabbos is prohibited, the use of dipsticks is permitted, as the patient is not interested in coloring the paper, but rather in obtaining medical information. A modification (shinuy) of the protocol is suggested, such as to prepare the bottle needed to collect urine prior to Shabbos and, if possible, to allow the urine to flow onto the dipstick, rather than to immerse the dipstick into the collected urine. An important qualification is that for medical reasons the collection and analysis of the urine was needed to be on Shabbos. If the procedures can be perfomed the following day when the person is at work, then these tests should not be performed on Shabbos. If needed, the person should not go to work on Sunday, but lose income and perform the needed urine collection and test on Sunday (7, 10).

·   To properly treat the patient, a physician wearing tefillin is permitted to take a urinal and so as to examine the urine.  Although preferable, the physician need not first remove his tefillin. It is permissible to collect urine from sick or healthy patients for analysis, even if done on Shabbos only for the sake of convenience. Furthermore, it is permissible to add a preservative to the container to prevent urine chemistry from changing (17).

In 1997, the article, “For everything a blessing” authored by Dr. Kenneth Prager, was published in the Journal of the American Medical Association. It is worthwhile to quote and to cite from this very powerful article. “When I was an elementary school student in Yeshiva - a Jewish parochial school with both religious and secular studies - my classmates and I used to find amusing a sign that was posted just outside the bathroom. It was an ancient Jewish blessing, commonly referred to as the Asher Yatzar benediction, that was supposed to be recited after one relieved himself. For grade school children, there could be nothing more strange or ridiculous than to link the acts of micturition [i.e., urination] and defecation with holy words that mentioned God’s name. Blessings were reserved for prayers, for holy days, or for thanking God for food or for some act of deliverance, but not for a bodily function that evoked smirks and giggles. It took me several decades to realize the wisdom that lay behind this blessing that was composed by Abayei, a fourth-century Babylonian rabbi.” 

The article continues with Dr. Prager’s description of an unforgettable patient, Josh, “a 20-year-old student who sustained an unstable fracture of his third and fourth cervical vertebrae in a motor vehicle crash. He nearly died from his injury and required emergency intubation and ventilator support. He was initially totally quadriplegic but for weak flexion of his right biceps.” After much time, incredible courage, hard work, and physical therapy, Josh improved and was able to walk slowly with a leg brace and a cane, but required catheterization. “The urologists were very pessimistic about his chances for not requiring catheterization. They had not seen this occur after a spinal injury of this severity.  Then the impossible happened. I was there the day Josh no longer required a urinary catheter. I thought of Abayei’s Asher Yatzar prayer. Pointing out that I could not imagine a more meaningful scenario for its recitation, I suggested to Josh, who was also a Yeshiva graduate, that he say the prayer. He agreed. As he recited the ancient bracha, tears welled in my eyes.” Dr. Prager concluded, ”Josh is my son ” (18).

Acknowledgement

Appreciation is expressed to Samuel (“Shimshon”) Koslowsky, an alumnus of Salanter Yeshiva, M.T.A. and Y.C. and a benefactor of SCW’s Derech HaTeva. A Journal of Torah and Science, for reviewing this manuscript.

References

1.   Steinberg, A., 2003, Encyclopedia of Jewish Medical Ethics, vol. 3, Feldheim Publ., NY, NY.
2.   Wikipedia, n.d., Urinary system, https://en.wikipedia.org/wiki/Urinary_system.
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5.   Mandar, R., 2013, Microbiota of male genital tract: impact on the health of man and his partner, Pharmacol. Res., 69:32-41.
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8.   Kumar, M., 2013, From gunpowder to teeth whitener: the science behind historic uses of urine,   http://www.smithsonianmag.com/ist/?next=/science-nature/from-gunpowder-to-teeth-whitener-the-science-behind-historic-uses-of-urine-442390/
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13.  Wikipedia, n.d., https://en.wikipedia.org/wiki/Urinalysis.
14. Cohen, S.B., 2008, Laws of Daily Living, vol. 1, Mesorah Publ., Ltd., Brooklyn, NY.
15. Chizkiyah, M., 2005, The Halachic Guide to Medical Practices on Shabbos, Targum/Feldhein, Nanuet, NY.
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17.  Steinberg, A., 2003, Encyclopedia of Jewish Medical Ethics, vol. 2, Feldheim Publ., NY, NY.
18.  Prager, K.M., 1997, For everything a blessing, JAMA 277:1589.