Despite the implied disgusting nature (especially smell) of urine, it is one of the most important types of “samples” used in medicine for diagnostic purposes. Like blood, urine can tell a lot about a person’s health and whether they have a certain disease or not.
One of the earliest recorded uses of urine as a medical test was for the detection of diabetes mellitus. People noticed that the urine of a diabetic would often smell quite sweet, and also taste sweet (it is uncertain how they came to test urine this way). This is because a diabetic has too much glucose (sugar) in their blood, causing it to spill over into the urine as the kidneys become saturated. In fact, the words diabetes mellitus stand for “passing through” (referring to the symptom of frequent urination) and “honey-sweet”. A completely unrelated disease called diabetes insipidus also causes frequent urination, but the urine does not taste sweet, hence “insipidus” (tasteless). This type of etymology is also seen in countries like Korea, China and Japan, where the word 당뇨(糖尿) literally stands for “sugar urine”. Although we no longer taste urine, it is still used to gauge the severity of diabetes by measuring the amount of protein in the urine (due to kidney damage).
There are many other tests one can do with urine to check for certain diseases. The chemical composition of urine tells us about the hydration status of a person, while giving away clues to diseases that cause electrolyte imbalance. It also gives some indication of how well the kidneys can do their job of concentrating urine. Certain markers such as white blood cells and bacteria in the urine can indicate a urinary tract infection. Antibodies in the urine can point towards a certain type of bacteria as the cause of a patient’s pneumonia, or whether a woman is pregnant (βhCG). Looking for proteins or sediments in the urine can be diagnostic of certain kidney diseases such as glomerulonephritis. Even rare diseases such as phaeochromocytomas can be diagnosed from the level of catecholamines in the urine (this is slightly too complex for our scopes).
A more interesting part of urinalysis is looking at the colour of the urine. Urine is usually a yellow colour, ranging in darkness depending on the concentration of urine. But when there are other things in the urine, the colour changes. Reddish urine suggests blood (which is not an indicator of kidney failure as TV shows say), which can be caused by trauma, UTIs, kidney stones or some other disease. Brown urine could be due to muscle breakdown somewhere in the body. Urine can appear very dark if the person has an illness called obstructive jaundice. Eating beetroots can cause your urine to turn bright red, while medications can change your urine colour from anywhere from red to orange to green. Murky or cloudy urine (with an offensive smell) may suggest a UTI.
Perhaps the most interesting urine colour known in medicine is purple. This unique colour is produced in a rare genetic disease called acute intermittent porphyria. If urine is collected from a patient suffering an attack of AIP (causes crippling abdominal pain) then left in the sun or under a UV light, it will turn purple due to certain proteins. Because of this, urine collected to test for AIP is wrapped in tinfoil before sending to the lab (where the chemicals are measured) to limit light exposure.
(Also read the article on how different colours of skin can be of diagnostic importance: http://jinavie.tumblr.com/post/32313894252/skin-colour)
It is interesting to see how people tend to use taste-related metaphors to describe other people. If a person is hostile or spiteful, we describe them as “bitter”. If a person is sullen and gloomy, we say they are “sour”. Perhaps the most extensively used taste is “sweetness”. People have a tendency of calling their loved ones sweet-related names, such as “honey”, “sweetie”, “sugar” or “sweetheart”. This is directly reflected in the tradition of giving chocolate to a loved one on Valentine’s Day. Quite obviously, this is because we find sweetness the most palatable taste and something that is nice. On a related note, could there be a relationship between sweetness and personalities?
A group of psychologists decided to study whether people who like sweet foods, or “sweet tooth”s, have a certain personality trait or not. They did a survey where participants were asked what foods they liked most out of a list of 50 foods covering five tastes (sweet, sour, bitter, salty, spicy). They also answered questions that gave an indication of their agreeableness (one of the five components of OCEAN personality traits). The psychologists then analysed whether there was an association between sweet tooths and agreeableness. Interestingly, a direct correlation was found between a liking of sweets and higher levels of agreeableness. This suggested that people who like sweet things tend to be more friendly, cooperative and compassionate.
But is the cause-and-effect relationship so simple? Could it be that sweet things cause people to be nicer? In a separate experiment, participants were randomly given a sweet food (chocolate), a not-sweet food (cracker) or no food. They were then asked to volunteer their time to help someone. It was found that those who were given something sweet were more willing to help another person compared to the other two groups.
This makes logical sense as eating sweets such as chocolate causes your brain to release a flood of hormones such as endorphin and serotonin from the absolute pleasure of the experience. These hormones make us feel happy, blissful and in love, which in turn make us more agreeable and willing to cooperate.
Although sweetness has numerous negative effects on the body such as weight gain and diabetes, there is no doubt that it is greatly beneficial for your mental health. If there is a bitter person around you, give them a good dose of chocolate to help them develop a sweeter personality. Or perhaps all they need is a sweet romance.
(Image source: http://fc04.deviantart.net/fs71/f/2010/138/c/e/Day_4___Sweets_by_Valandill.jpg)
Diabetes is a common and serious disease that is caused by the body being unable to control the blood sugar (glucose) level, leading to severe organ damage. For example, blood vessel damage can lead to blindness, renal failure, heart attacks or strokes. Diabetes is divided into Type 1, caused by the destruction of pancreatic β-cells (that produces insulin) leading to insulin deficiency, and Type 2 diabetes, where insulin resistance renders the hormone useless. Thus, diabetes is a disease related to insulin. So what is insulin?
Insulin is a hormone that lowers blood glucose. It has the important function of controlling blood glucose levels after a meal. Therefore, a diabetes patient has high blood glucose, which has a toxic effect.
As type 1 diabetics cannot produce insulin, they require daily insulin injections. Some type 2 patients also need insulin. But this hormone that saves the lives of diabetics also has a deadly dark side.
Too much insulin leads to hypoglycaemia due to its blood glucose lowering properties. This is the opposite of what happens in diabetes, but is even more dangerous. Although there are in-built autonomic defence mechanisms to prevent this from happening, a high level of insulin can overcome this to cause blood glucose to plummet.
A hypoglycaemic patient initially suffers cognitive dysfunction, then sweating and tremors. As blood glucose falls further, the patient begins to convulse, until they fall into a coma and eventually die. This is because the brain heavily relies on glucose for its functions, and a disruption of glucose supply causes it to shut down.
Because blood glucose fluctuates much like blood pressure, it is hard to control. This leads to many diabetics accidentally falling into hypoglycaemia, or even losing their lives. Furthermore, insulin is sometimes used by people to cause hypoglycaemia as a means of suicide.
If you see a person convulsing, check around for any hypodermic needles or bottles of insulin. A diabetic patient would have a medic alert bracelet, and if it is a suicide attempt they would have recently injected themselves with insulin. If you think it is hypoglycaemia, you must immediately treat the patient as severe complications can occur in a very short time. The emergency treatment is quite simple – raise the blood glucose. For example, dissolving a spoon of white sugar in the patient’s mouth or making them drink a sugary drink such as apple juice can cause a spike in blood glucose, causing the symptoms to disappear. If their consciousness does not return, you may need to repeat the process until their blood glucose is high enough.
Knowing even a little about insulin and hypoglycaemia may lead to you saving a person’s life someday.