Over 6000 years ago, physicians began using urine to diagnose illnesses. Physicians back then referred to urine as a “divine fluid” and thought of it as a window into the body.
This is still true today, however our methods have become more sophisticated. Physicians can now detect and manage disorders such as urinary tract infections, kidney disease, cancer and diabetes through urine testing.
Additionally, modern urinalysis diagnostics have become very simple, allowing us to detect indicators of pregnancy, ovulation and other health issues in the comfort of our own home.
How did it start?
In the ancient world physicians would observe urine visually, called Uroscopy. Records on clay tablets have been found from the Babylonian and Sumerian physicians of 4000 BC. This practice was continued by the Egyptians and Greeks.
Medical works describing 20 different types of urine have been found in ancient Sanskrit literature (500 AD). In particular, Indian physicians are credited for the discovery of an indicator of diabetes. They found that black ants were attracted to the sweet tasting urine from these patients.
Hippocrates (460-370 BC) discovered an indicator or kidney disease after analyzing the bubbles that lay on surface of fresh urine. He also linked fever with sediment on the urine and found that sediment in the urine increases with progressive rise in fever. Galen (129-200 AD) refined the Hippocrates ideas and concepts for urine analysis. He referred to polyuria, a condition where the body urinates more than usual and passes excessive large amounts or urine as “diarrhea of urine.”
Urinalysis gains popularity
By the middle ages, it was believe that nearly every disease could be identified by urine examination.
Ismail jurjani, an 11th century physician, worked on the collection of urine for laboratory examination. He explained that urine should be collected over a 24 hour period in a large clean vessel and it shouldn't be kept in heat or sun which can alter urine color. This practice was thought to reflect the best medical system for centuries and is still used today to check kidney function.
Urine testing and Uroscopy entered the household through the medical manuscript "Fasciculus Medicinae" during the renaissance. Using this reference, uroscopy was considered so easy that anyone could learn it.
The invention of the microscope by Hans and Zacharias Jensen expanded the field of urine examination and led to the identification of stone fragments in urine in 1630, and urinary crystals in 1665. Microscopy was introduced into clinical practice in 1830 and was first used to detect cancer cells in urine in 1865.
The first modern tests to accurately detect pregnancy using urine were developed in 1927 by German Scientists, Ascheim and Zondek but took months for the results. Several decades passed before this diagnostic was simplified enough to be done in doctor’s offices, and it was not until the 1970s that the at-home pregnancy test hit the market.
For bladder and urinary tract related cancers, complex molecular diagnostics which require expensive laboratory equipment are still the norm. In the 1990s, enzyme-linked immunoassays were first used to detect cancer cells in urine.
Nowadays, a combination of historical and modern methods of urine inspection are used. Modern physicians still inspected urine visually, then under the microscope and finally with molecular diagnostics. Using these three methods, they can identify of a variety of health indicators and disorders.
As more methods are developed, perhaps the idea from the middle-ages that nearly every disease could be identified by urine examination can still hold true today.