Abstract
The color of urine is an important factor in urine examination, which can help physicians differentiate various diseases. Today, it is known that certain dyes, drug intoxications, and diseases can induce green urine discoloration. In the view of traditional Persian medicine, which is based on humoral medicine, green urine discoloration is generally referred to the dominance of coldness in the body. In fact, it is considered to be a result of a special kind of humoral imbalance and fluid depletion or retention in the human body. Persian scholars believed that green urine could be an indicator of intoxication or a predictor of an imminent spasm or convulsion in pediatric patients. Further investigations could result in finding new diagnostic scales of urine color based on the teachings of traditional Persian medicine.
Urinalysis is considered to be the third common diagnostic laboratory test worldwide. 1 It plays an important role as a primary test and helps the physicians diagnose and make decisions. Urine color is one of the important attributes of urinalysis, which is shown to be useful in differentiating various medical situations. 2
In ancient medical practices, as suggested by the retained manuscripts, urine examination and specifically urine color has been frequently reported as a crucial diagnostic material for a wide variety of illnesses. 3,4 An example of such ancient medical practice is traditional Persian medicine, which, despite its long history, is considered today as a new brand of complementary and alternative medicine. In traditional Persian medicine, the importance of urine as a diagnostic tool is considered to such an extent that it is called Tafsareh, which is translated as “what by means of which diagnosis is to be known.” 3,5
Persian sages such as Avicenna (980-1037
Painting of urine examination by Rhazes in Gerard of Cremona’s “Receuil des traités de medicine”
Qarooreh, a glass jar similar to the shape of urinary bladder.
Ancient Persian physicians were aware of coloring agents in some vegetables and spices such as cassia (Cassia fistula), leek (Allium porrum), and saffron (Corcus sativus), which, respectively, cause red, green, and yellow discoloration of urine. Henna (Lowsonia inermis), which was utilized as a skin and hair dye, was also known to induce red discoloration. 10 In addition, lack of sleep, fasting, intensive workout, and excessive anger were known to be the cause of dark yellow or red urine discoloration. 3,5
In traditional Persian medicine, the color spectrum of urine has been divided into 5 segments, namely, Asfar (yellow), Ahmar (red), Akhzar (green), Asvad (black), and Abyaz (white). 3,4 Each segment of the spectrum is further categorized into subcategories. In this study, we focus on differential diagnosis of green-colored urine from the viewpoint of both conventional medicine and traditional Persian medicine.
Methods
A review of the conventional medicine literature was carried out by the authors through PubMed and Google Scholar databases focusing on the keywords “green urine,” “urine color,” “urine discoloration,” and “urine analysis.” Then, differential diagnosis of green urine from the conventional medicine point of view was summarized in a table. In addition, the authors carried out a thorough review of the matter through major sources of traditional Persian medicine, such as Canon of Medicine by Avicenna, Zakhireh-e-Kharazmshahi by Jorjani, and Kholasat-al-Hekmah by Aghili Shirazi Khorasani. The findings were summarized in another table. At the end, a comparison was made between the causes of green urine discoloration from the perspectives of conventional medicine and traditional Persian medicine.
Green Urine in Conventional Medicine
Although green-colored urine is not a usual medical manifestation, its occurrence could be a clue to some special conditions. 11 One of the most common causes of green urine that has been frequently reported in the literature is propofol injection. 12,13 It is a well-known side-effect of this commonly used anesthetic drug, which is mainly caused by the phenolic green chromophore resulting from propofol conjugation in the liver. 14,15 Here, we categorized the reasons for green discoloration of urine from the perspective of conventional medicine into 4 major groups, namely, drugs, dyes, diseases, and miscellaneous (Table 1). 11 , 16 –23
Causes of Green Urine Discoloration in Conventional Medicine.
Green Urine in Traditional Persian Medicine
Similarly, the causes of green urine from the traditional Persian medicine perspective are categorized into the same 4 major groups as listed in Table 2. 3 –5 , 9 , 24 –26 In contrast to the conventional medicine standpoint, traditional Persian medicine clusters the green spectrum of urine into 5 groups determined by the following colors: Fastaghi (pistachio), Asmanjuni (sky-green), Nilji (emerald green), Korrasi (leek green), and Zanjari (verdigris). An estimation of these colors is illustrated in Figure 3. Of course, some ancient Persian physicians have added another color, Zeyti (olive) color, as an additional group. 3,5
Causes of Green Urine Discoloration in Traditional Persian Medicine.
Estimation of green (or blue-green) spectrum of urine in traditional Persian medicine (The color version of this figure is available in the online version).
Each one of these colors has a special meaning as described below:
Fastaghi, which is a mixture of yellow and a little black (eg, the color of pistachio), corresponds to cold temperament as Avicenna and other Persian scholars have mentioned.
4,27
In Description of Canon, Ibn Nafis Qarshi (1210-1288
Asmanjuni is the color of a cloudy sky with a mixture of black and white and the dominancy of blackness, which indicates the congelation of humor components or combination of Sauda with watery moisture. It should be noticed that the blackness here cannot be related to Safra combustion because it is pure black with no yellowish color. 3,4 In addition, some lethal poisons can induce this color in the urine, especially those that may cause hypothermia. 3,29
Nilji is similar to the color of indigo-infused water. Nilji is a combination of 3 colors: black with a little white and blue, with the dominance of blue color. This implies coldness and congelation of material components. 3,4
Korrasi is similar to the green color of leek leaves, implying excess heat and combustion. 3,4
Zanjari is similar to the color of verdigris, and due to the complete combustion, its green is tending to whitish. It could be said that Zanjari is the ashes of humors, which is excreted by urine. Appearance of Zanjari urine after excessive fatigue is a strong indicator of upcoming spasm or convulsion. 3
The last 2 colors (Zanjari and Korrasi) may be seen in the state of Safra excess in the stomach in which Safra may be vomited. However, Zanjari is more noxious than Korrasi (due to its maximum combustion) and could be considered as toxic. 4,5
It is worth mentioning that both Asmanjuni and Nilji colors of the urine could be indicators of a forthcoming paralysis, repletion-caused spasm, or convulsion in children. In addition to the weakness of their neural tissue, phlegm (the cold and wet humor) in children’s bodies is more than in adults. Accordingly, residues of other parts of the body and even their body phlegm itself could be shed in the neural tissue more easily. Therefore, if this excess moisture become viscous (solid), it may result in repletion-caused spasm or convulsion (Tashannoj-e-emtelaee). 3 –5
Discussion and Conclusion
Generally, traditional Persian medicine scholars believed that if green urine is caused by combusted materials, it will result in dryness-caused spasm or convulsion, and if it is due to moisture congelation—as mentioned above—it will cause repletion-caused spasm or convulsion.
They also believed that green urine would result in black urine in most cases and sometimes it will indicate Jozam (leprosy). 3 Worthy of mention is that hepatorenal involvement could occur as a complication of leprosy. Elevation of hepatic enzymes besides liver histopathological changes would result in jaundice. 31,32 In this regard, accumulation of bilirubin and biliverdin in blood and consequently their urinary excretion is responsible for yellow-green color of urine. 33 Moreover, darkness of urine, due to the presence of bile products after liver damage, 34 is another fact that upholds the idea of traditional Persian medicine sages.
Interestingly, similar theory has been presented in traditional Chinese medicine. It has been stated that phlegm-fluid retention can lead to pathological changes like spasm, cramps, and stiffness. 35 However, sometimes this excess moisture remains thin and watery, and then, infiltration of this less viscous moisture in the neural system or fascias may induce paralysis. 3,4,9,30
In allopathic medicine, some rare conditions such as familial benign hypercalcemia (blue diaper syndrome) can cause green urine. 36 Although hypercalcemia is less common in children and may be accompanied by nonspecific clinical features, severe hypercalcemia can seriously affect the nervous system. It may cause weakness, decreased level of consciousness, and even seizure. 37
On the other hand, as viewed by the modern medicine, muscle cramps could be secondary to metabolic disturbances such as hypercalcemia, fluid retention, acute extracellular volume depletion, and liver and kidney disorders. 35
It can be concluded that green discolored urine in conventional medicine is mainly attributed to intoxication with special drugs and chemicals (most of which can cause hypothermia) in addition to some specific diseases. In traditional Persian medicine, however, green urine is generally referred to the coldness dominancy in the body, which is mainly a result of some sorts of humoral imbalances and fluid depletion or retention. It not only could be a representative of intoxication but also may be a predictor of imminent spasm or convulsion in pediatric patients.
It seems that urine color could be more beneficial in the realm of diagnosis—and even prognostication of impending diseases—than it is thought to be. Further investigations are guaranteed to find out tangible evidence of new diagnostic values of urine color as inspired by traditional Persian medicine ideas.
Footnotes
Acknowledgments
The authors would like to thank Dr Soheil Kolouri and Research Consultation Center of Shiraz University of Medical Sciences for linguistic improvement of the article. Also, Dr M. B. Minaei and Dr M. Seddigh are appreciated for their work on urine color in traditional Persian medicine and Dr M. Heydari for his useful comments.
Author Contributions
SK contributed in data gathering and writing the draft. BD wrote the draft and contributed in data gathering and writing the final version of the article. AMJ and VT contributed in revision and correction of the article.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Ethical Approval
Ethical approval is not required for this study as no human subjects were involved.