Posted in Psychology & Medicine


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:

Posted in Psychology & Medicine

Process Of Elimination

“How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?” ~ Sherlock Holmes

If there is not enough evidence to come to a conclusion of what is the truth, start by removing the possibilities that cannot be true. If you hack away these impossible answers one by one, you will ultimately end up with the truth. This method is highly useful in a multiple-choice type exam, where you cross off the false answers until only one remains (or take an educational guess from whatever remains). In medicine, a process of elimination can be used to narrow down a differential diagnosis, or to reach a diagnosis of exclusion – that is, a diagnosis that cannot be proven to be true but seems to be the only one that fits since all other diagnoses do not. 


Posted in Psychology & Medicine


Blood, which supplies all the cells in the human body with nutrients and oxygen, flows through the vessels due to the pumping of the heart. Thus, blood flow directly transmits the force generated by every heartbeat. As the blood ejected by the heart causes the arteries to “pulse” by stretching and relaxing. As some pulses can be felt over the skin, they are very useful in patient examinations, especially a clinical exam of the cardiovascular system. Although people commonly know how to take a pulse from the wrist or neck, there are many more places a pulse can be taken from.

  • Radial pulse: Taken from the inside of the wrist on the side of the thumb.
  • Brachial pulse: Taken from the inside of the elbow.
  • Carotid pulse: Taken from where the neck meets the jawline, or 2~3cm either side of the Adam’s apple to be precise.
  • Apex beat: This measures the heartbeats directly, taken on the left chest between the 4th and 6th ribs (around the left nipple).
  • Abdominal pulse: Taken from above the belly button of a lying patient, may be able to see the pulse.
  • Femoral pulse: Taken from the middle of the groin. 
  • Popliteal pulse: Taken from the inside of the knee.
  • Posterior tibial pulse: Taken from the inside of the ankle behind the bone.
  • Dorsalis pedis pulse: Taken from the back (upper side) of the foot along the middle.

When taking a pulse, you use your second and third fingers (and the fourth if you want) and press lightly on the pulse point. If you press too hard, you may stop the blood flow and obliterate the pulse. As a pulse is measured per-minute, it is often taken for 10 or 15 seconds and multiplied by 6 or 4 respectively. Also, it should be noted whether the pulse has a regular rhythm, and if it is irregular, whether it is regularly irregular or irregularly irregular. If the pulse is over 100 beats per minute, it is called tachycardia, while less than 60 beats per minute is referred to as bradycardia. If it is irregular, it is called an arrhythmia.

An experienced doctor can diagnose different conditions such as an aortic stenosis or atrial fibrillation just from taking the pulse of the patient. Taking a pulse is also a crucial diagnostic tool in traditional Korean and Chinese medicine.


Posted in Psychology & Medicine


Hysteria is a disease that was believed until the late 19th century to be a disease unique to women due to a pathology of the uterus (hystera is Greek for uterus). The most common symptom was mental disturbance (such as extreme moods) accompanied by shortness of breath, vaginal dryness, nervousness, insomnia, oedema, faintness and many more. The treatment back then was for a physician to massage or stimulate the patient’s vagina to induce an orgasm. By the 19th century, the treatment evolved and involved vibrators and water massage machines.

This disease was first noted by Hippocrates, the father of modern medicine. Galen, another famous physician in the 2nd century, believed it to be caused by sexual deprivation. Thus, sexual intercourse was prescribed as treatment in the Middle Ages.

Modern medicine no longer recognises hysteria as a medical condition and is now referred to as sexual dysfunction (the sexual treatments described above are no longer used either). However, there is a condition called mass hysteria that indeed exists.
This is a psychological phenomenon rather than a disease, commonly occurring in closed spaces such as planes or in crowds in a state of panic. When a high tension situation arises, people easily become delusional and believe that they are suffering from a disease. The body reacts to this with actual symptoms such as a psychosomatic rash. These symptoms can be as severe as fevers, vomiting and even paralysis.

If many people are all complaining of similar symptoms and infectious disease seems unlikely, there is an easy way of diagnosing mass hysteria. Tell the patients that they have a rare disease and begin listing the symptoms they complain of. At the end, make up a false symptom (e.g. “shaking of the left hand”). If the patients all suddenly start to shake their left hands (which causes them to panic more), it is likely that their panicking brain is causing the symptoms rather than some pathogen. Symptoms subside after the patients relax.

Interestingly, mass hysteria affects women much more than men.

Posted in Psychology & Medicine


A man comes in to a clinic and tells the doctor that he is in great pain.
It hurts if he prods his arm with a finger. The same applies to his leg and his torso.
He says that after looking on the internet, he is sure that he has fibromyalgia syndrome, and asks to be prescribed some painkillers. Also, he is worried that it could be necrotising fasciitis and demands a biopsy and antibiotics.

The doctor, without saying a word, gently grabs his hand, then squeezes his index finger. The man feels a shooting pain and screams in agony.

The diagnosis? A broken finger.