Human beings have believed that all matter can be divided into basic elements for a very long time. Although we now know that the basic building block of the universe is atoms, what did ancient people believe matter was made of?
In ancient Greece, the seat of Western culture, it was believed that everything was made from the four elements: earth, fire, water and air. According to Aristotle, every element has a primary and secondary characteristic, with the four characteristics being hot, cold, dry and wet. Air is primarily wet and secondarily hot, fire is primarily hot and secondarily dry, earth is primarily dry and secondarily cold and water is primarily cold and secondarily wet. He also spoke of a fifth element (quintessence) beyond the four elements. The name of the fifth element is aether and it is a pure and heavenly element that cannot be corrupted like the earthly four elements. Furthermore, it was thought that aether was the element of the sky and stars were composed of it as they were heavenly, not earthly.
The four classic elements of ancient Greece had an impact not only on physics and chemistry, but also on philosophy and culture (the concept of the four elements is popular in modern games too). The most interesting example of these is a theory by Hippocrates, the father of Western medicine, that states that the human body is composed of four bodily fluids (humours) and an imbalance between the humours caused diseases. The four humours are yellow bile (fire), black bile (earth), blood (air) and phlegm (water). Furthermore, he believed that the four humours affected personalities too. For example, an excess of black bile (“melan chole” in Greek) would cause a person to become introspective and think negatively, leading to depression or “melancholy”. This is quite possibly the first medical records on clinical depression.
The four classic elements of ancient Greece can also be found in ancient Egypt and many other ancient civilisations. It also had a significant influence on alchemy in the Middle Ages.
(Image source: http://y3rk0.deviantart.com/art/The-Four-Elements-87598175)
Among the thousands of signs and symptoms in the field of medicine, there is one that every doctor and medical student knows since the development of medicine. Clubbing is an easily noticeable sign in a patient’s fingers that can have wide implications on their health.
Clubbing is essentially when the angle (gap) between the fingernail bed and finger disappears. The formal definition is much more complicated, such as “the loss of the normal <165° angle, or Lovibond angle between the nailbed and the fold”, but for all intents and purposes the simple definition is sufficient.
To see if a patient has clubbing, the physician carefully studies the fingers against light. There are a few ways to check for clubbing but the most popular methods are holding the fingers out straight and holding them parallel to the ground, checking the angle between the nailbed and finger, or the Schamroth’s window test. The latter test is done by holding two opposing fingers (such as the left and right index fingers) against each other nail to nail. The fingers are then held against the light so that the light can shine through the “window” that is made. If the window is not seen, the test is positive and the patient has clubbing.
What does clubbing suggest? Clubbing was first noticed by Hippocrates, the father of Western medicine, who observed that people with clubbing tended to grab their chest and fall dead. This is one of the most common associations to clubbing – a congenital cyanotic heart defect such as tetralogy of Fallot or patent ductus arteriosus. Other common associations are related to the lungs, such as lung cancer (one of the most common causes) and various other lung diseases such as interstitial lung disease, tuberculosis and other chronic infections. There are also a myriad of other diseases associated to clubbing, including but not limited to: Crohn’s disease, ulcerative colitis, cirrhosis, celiac disease, Graves disease and certain types of cancers (lung, gastrointestinal and Hodgkin’s lymphoma mainly). Clubbing can also be idiopathic, where there is no apparent cause for the clubbing and the person just has it (possibly just born with it).
Despite knowing about clubbing for over 2000 years, we still do not know the exact reasons for clubbing. There are theories that it is related to a fall in blood oxygen content leading to vasodilation in the peripheries. As the pathophysiology is not clear and so many diseases are associated with it, when clubbing is found in the patient the physician should investigate the related organ systems (heart, lungs, GI mainly) to narrow down the possible cause of it. As many of the causes (such as lung cancer) carry a rather morbid prognosis, it is quite important to notice whether the patient has clubbing when doing a physical examination.