Waterworks – an unsavoury subject or what?

Little do we know but your urine holds the secrets of health. Why do you need your blood pressure and weight checking? And what is all this about needing a water sample!

Hippocrates, often called the father of Western medicine, said “No other organ system or organ of the human body provides so much information by its excretion as does the urinary system.”

medieval medicine

Our waterworks has been a significant subject in medicine since the earliest of times. A podiatrist will first see a swollen ankle and work out whether the patient is wearing the proper footwear. Next, they might need to work out how healthy their patient is. Today, and certainly in the UK, even primary medicine might miss essential disease because of the ‘C-word – sorry to be clear, corona virus! Four percent of my patients were diagnosed with diabetes not by the GP but by my team. However, it would be irresponsible to suggest that the C-word caused this problem  – because it did not. I do not intend to stray into medical politics. General medical practice has been working inefficiently for many years; the narrative will become who’s fault?

This article provides a whistle stop tour to illustrate the main secrets of health held by urine and the kidneys. The process is complex and to aid the reader some sections are linked to explanation provided by other useful sites and contain educational video material. Many of these sites have adverts but this does not remove their value as useful educational material.

The Podiatrist and the kidney

Podiatrists are just one group of medically trained clinicians who look out for diseases and make sure medical care is delivered. They are part of the Primary Care Team. So, forget the idea that you are getting a pedicure and understand why you might be paying a little bit more than you thought because podiatrists have responsibility for medical health. You have entered a clinic with rather more expertise than you might have expected.

In the past, physicians would hold up a sample of urine to the light and declare all manner of diagnoses. As a podiatrist in training, colour became a prodigious indicator of so many aspects of medical assessment – the colour of the lips for oxygen exchange, the skin and blemishes for cancer, the colour of the nail bed for heart and lung as well as kidney disease. In every case, subtle colour changes might have played a part from the yellowing features created by jaundice and hence a sign of liver malfunction to the loss of pigment in black skin – vitiligo. When it came to body waste, it was easy to assume this had nothing to do with the podiatrist, and yet in one of the more memorable lectures in clinical medicine. In diabetes, the kidney is affected and leaks sugar in the waste fluid we know as urine; ‘urina’ in Latin, ‘ouro’n in Greek, old English ‘waer’ and old Norse ‘ur’ meaning drizzling rain. Water is at the root of the word, making sense as 70% of urine is water. The sugar changes the concentration of urine, and it tastes sweet. Mellitus in Latin is sweet, while diabetes is Greek for siphon. And so the Professor points out the best way to test a patient’s urine is to dip the finger into the container with the latest urine sample. One sucks the finger to test for that sugary taste, but he doesn’t tell his medical students this was a feint. He uses a different finger to pop into his mouth rather than the one demonstrated in the urine sample. Doubtless, many physicians used the oral method to detect diabetes, but today we can use a small stick that takes the place of the finger in a somewhat more convenient way. Podiatrists spend many hours studying diabetes and checking the values of urine and blood in their patients.

Chronic kidney disease (CKD)

Chronic kidney disease (CKD) causes 40-45,000 premature deaths in the UK every year, and sadly this includes children. Uncontrolled diabetes and high blood pressure are the most significant causes. Black, Asian, and minority ethnic communities are five times more likely to develop CKD than other groups. Without your kidneys, you will die, and if not, you will need an artificial system called dialysis or a kidney transplant.  Therefore, it would be misleading to say that urine does not interest any medically trained clinician, many not being principle physicians. Urine holds the secrets of the kidney and its state of health.

Balancing salts

When I was studying biology at A level, I had a fascination for the different kidney structures from camels to humans. Within the characteristic curve shape of this dark browny-red organ, nephrons make up that portion of the kidney responsible for preventing water loss and balancing our salt balance. These structures number up to a million in each of our two kidneys. The section for making urine concentrated is called the Loop of Henle. Camels have a very long loop compared to humans, desert rats even longer and this is why they cope so well for so long without water. If we fail to drink water over a period of time, or the temperature increases so that we sweat more, the urine turns yellow. If we drink plenty to restore matters, the colour becomes clearer like water. Camels can cope better because they can deal with this concentration and recover faster than we can if we dehydrate. The working (physiology) of maintaining fluid balance is quite complex, but a YouTube video (click on nephrons) can help build on the explanation if you wish to understand more about nephrons. The kidneys perform other crucial functions apart from maintaining overall fluid balance. These can be summarised as –

  • Filtering waste materials from food, medications, and toxic substances.
  • Creating hormones that help produce red blood cells, promote bone health, and regulate blood pressure.

Controlling blood pressure with medication

Hormones help the kidneys work correctly, but for those of us that treat the musculoskeletal system, maintaining a healthy bone structure is vital and keeping our blood pressure between those values of 60-90 mmHg at rest and when pumping out the higher value of 100-140mmHg. Pressure increases because the stiffness in the walls of blood vessels as we age and resist the flow of blood. Some blood pressure medications work on the kidney and are called ACE inhibitors. Others are called diuretics – meaning producing more urine.

Suppose we have too much water in our bodies. In that case, our kidneys may not be working so well and cause swelling within the tissues as water is forced out into the interstitial (space between cells) regions of the body, such as the ankles and legs, and eventually around the buttocks in severe cases. When the water reaches an incorrect balance, the heart cannot cope, and even the lungs are at risk. Above the kidneys, a special gland called an adrenal gland exists and produces a hormone that corrects the water loss pushing more water back into the body. One of these hormones is called angiotensin. To reduce this water overload, which increases the volume of flow and blood pressure, angiotensin can be turned off by inhibiting its action. The angiotensin-converting-enzyme is inhibited with the drug group called ACE inhibitors. Diuretics are different drugs and prevent sodium chloride from being absorbed via the Loop of Henle. This, in turn, stops water from being saved and is pushed out with more frequent trips to the toilet/bathroom. Again blood pressure is reduced. Diuretics are inconvenient to disabled people who cannot move easily due to stiffness, poor muscle control and weakness and arthritis. Podiatrist are heavily into disability, fall and efficiency body movement. How can you not understand the background of disease?

Poor bone and joints

If blood pressure is related to volume build-up, we need to understand that urine also contains salts such as sodium, chloride, potassium, calcium and phosphate. These elements fluctuate but are balanced using the nephron system briefly described. A build-up of urea and creatine is unwelcome, being nitrogen based waste products. Meat is digested in the body and purines are excreted after being converted to uric acid. A failure of this process leads to the condition of gout – this is where urate crystals build up around joints causing pain, toes and the ankle are targeted.  

Bones require calcium and phosphate salts and it might not come as a surprise that kidneys regulate these two elements. We can see that kidneys affects a fair amount of body function by now. The process is controlled by glands and hormones; the parathyroid are 4 small glands near the windpipe and the thyroid gland. The parathyroid hormone (P.H) works on the kidneys to balance calcium and phosphate. If too much P.H hormone is produced, this will remove calcium from the bone and pushes this salt into the blood so that bone will weaken. Fractures can arise in any load-bearing bone, and the foot is not excluded in this regard.

The process of regulation is part of the negative feedback process. If too little of one element occurs in the blood, such as calcium, it has to come from somewhere else – the bone. The kidney can control what it wants to pass into the blood, so the hormone works to achieve this. Vitamin D is converted to an active form called calcitriol and this is monitored through a negative feedback system. The balance between phosphate (phosphorous) and calcium need to be maintained in the blood and bone maintenance. Calcium affects nerve control and heart function, so everything becomes linked to health in reality. The heart is a pump, and if this fails because the kidneys fail, the body will become feeble over time; feet will swell, bones might break and blood pressure rises.

Examining the colour of your watery efforts

The grades of urine colour varies. As urine become concentrated, the odour changes. Foods will cause colour change and affect odour. Too much beetroot can make urine pink. A human being, a filthy animal at times, sometimes leaves its scent with strong aromatic ammonia in various corners of our world, namely walls and underground spaces. The smell is also caused by bacterial growth which itself causes the pungent smell. Infected urine has a curious odour and those clinicians of old would also make a judgement on the change in fragrance. Infection that passes through the kidney will change the clear or yellowish urine from red to brown and white in rarer cases. The white colour may be related to calcium or phosphate minerals or a fungal infection. Redness may be simply due to a patient having done a rigorous run which we call runners haematuria – blood in the urine. Red blood cells are damaged and excreted in the waterworks. Women may have blood through normal menstruation. Black liquorice and asparagus can turn urine blue or green and yet again, it might be an infection. Laxatives and fava beans can turn urine brown.

Taking action

Low back pain, pain when passing urine and dark red colour changes require urgent medical attention, which means seeing that GP or NHS 111. Routine checks where cases are known or being treated are essential. Renal cancer and cancer of the bladder or prostate are less well recognised than other cancers. Urine flow and comfort will alter with disease. Of course, sometimes infection and cancer are silent; painless is more worrying as it can be ignored. Men with water flow problems should seek medical advice as much as women. Those who fall into the ethnic minority groups or come from families with poor renal health should be screened. The podiatrist might not treat you for chronic kidney disease (CKD), but our function is to work as a medical team to ensure health does not worsen to the point that it is too late or that appropriate treatment cannot be undertaken.

So even if you don’t have a urine test or blood pressure assessment, ask your podiatrist to do one. These tests are simple, non-invasive and can tell us a good deal more than you might realise. Podiatrists care about the whole body, not just feet.

J.A. Armstrong, Urinalysis in Western culture: A brief history, Kidney International, Volume 71, Issue 5, 2007, Pages 384-387, ISSN 0085-2538, https://doi.org/10.1038/sj.ki.5002057.

Watson, Kathry. 2018 Urine colour chart. Is Blue Urine Normal? Urine Colors Explained. 

On Consultingfootpain site

Thanks for reading Urine Holds the Secrets if Health by David R Tollafield

Published by Busypencilcase Communications Est. 2015

12th January 2022