Most people think that medical humor consists of doctor and HMO jokes (and some of it does) but in medicine the word "humor" has another sense and refers to a fluid (or semifluid) substance.
The aqueous humor and the vitreous humors are fluids within the eye. The aqueous humor is the watery fluid normally present in the chambers of the eye around the iris while the vitreous humor is the "glassy" fluid behind the lens in the eyeball.
The humors (humours, in England) originated in an ancient theory that held that health came from a balance between the bodily liquids. These liquids, the humors, were four in number:
- Phlegm (water)
- Black bile or gall (secreted by the kidneys and spleen)
- Yellow bile or choler (secreted by the liver)
Disease arose when imbalance occurred between these four humors. The treatment of disease was simple, straightforward, and logical (assuming the humoral theory to be correct).
The doctor needed first to diagnose the humoral imbalance. Then if one humor were deficient, the doctor had to strengthen it. And, conversely, if another humor were excessive, the doctor needed to purge it.
Take a person who was "bad-humored" because of too much blood. Superfluous blood was removed by bleeding the patient or applying leaches to suck out the extra blood. By such means, the person became "good-humored."
This theory (which is variously called the humoral theory, humoralism, and humorism) has been ascribed to ancient Greek writers at the time of Hippocrates. Hippocrates' inexact dates were about 460 to about 375 BC. But, in truth, the theory was devised well before Hippocrates and it was widely believed for over two thousand years.
The four humors did not just explain health and disease. They were believed to correspond to the four principal temperaments:
- Phlegm to the phlegmatic (laid-back) temperament
- Blood to the sanguine (passionate) temperament
- Black bile to the melancholic (sad) temperament
- Yellow bile to the choleric (angry) temperament
If someone was both depressed and angry, he or she obviously had too much black and yellow bile. Any temperament could be explained by an appropriate blend of humors.
The humoral theory was not definitively demolished until Rudolf Virchow published his formative book, Cellularpathologie (1858), in which he persuasively set forth the cellular basis of pathology. Pathology today rests on Virchow's cellular (and the new molecular) foundation.
The four principal humors have been happily dispelled, leaving in their wake the aqueous and vitreous humors, and the recommendation to drink plenty of water every day- especially during the summer months!