From time to time patients ask me if I do surgery. Of course, what they mean is do I perform minor surgical procedures, since it is obvious I’m no surgeon. I tell them, yes, I can biopsy spots on the skin, lance boils and sew up lacerations. In medical school I learned to repair torn flesh by working in an inner city ER repairing the nightly wounds of the “Knife and Bottle Club.” I jokingly tell patients that I could probably take out their inflamed appendix, but they may never be the same again!
On my desk is a bust of Auguste Rodin’s The Thinker. This sculpture was made somewhat famous in the pop culture sitcom, Dobie Gillis. The show often pictured Dobie with his chin on his hand in deep thought, just as Rodin sculpted his vision of a man in contemplation. I often quip as I point to The Thinker, “I’m a thinker, not a cutter.” Of course surgeons are thoughtful as well, but surgical disciplines focus on operative procedures. Internists are diagnosticians and focus on medical, rather than surgical, therapy.
Internists are specialists in medical diseases of adults and should not be confused with the antiquated word intern. In the past a doctor in his first post-doctoral year of training was referred to as an intern. I won’t bore you with the new politically correct terminology; just remember that virtually all doctors these days have three or more years of residency training in their specialty after medical school. Internists are analogous to pediatricians, who are specialists in childhood medical diseases. Some internists pursue additional post-residency training called a fellowship. An example is cardiology, a sub-specialty of internal medicine. Many surgeons pursue additional post-residency training as well and focus on vascular surgery, as an example.
There is a notion in science that if you break down a complicated system into its integral parts and figure out how each part works you’ll be able to understand the whole. This perspective is called reductionism and is a fundamental principle of all scientific inquiry. The trick is to not lose the forest for the trees because I believe we are all more than the sum of our parts.
Nephrologists are internists who have sub-specialty training in medical kidney diseases. Just as I have sub-specialist training in geriatrics (a specialist in older adults), nephrologists are doctors who manage end-stage kidney disease and difficult diseases such as nephritis (kidney inflammation).
Most of my readers are old enough to remember tea strainers and ice picks. In times past we put tea leaves in a strainer composed of fine mesh. Hot water is then poured over the tea to produce a cup of tea, much like my modern drip coffee pot that makes my cup of Joe every morning. Imagine the kidneys as a filtering system composed of several million filtering units called nephrons. As blood courses through the kidney it is filtered and waste products are removed. The large proteins and blood cells are held back by the filtering mesh. Diseases sometimes damage the mesh filter analogous to poking a tea strainer with an ice pick. Large proteins and cells can then stream through.
The kidney does more than just filter waste. It also helps to control salt and water balance in the body. A common problem internists and nephrologists deal with is sodium or salt imbalance in the body. Dehydration may decrease blood flow to the kidney and lead to a buildup of waste products in the blood stream. A more complicated situation results when water and salt balance are altered and hyponatremia (low sodium) results. This is a complex issue, but suffice it to say that a low blood sodium value is not due to a deficiency of salt as much as it is due to water and sodium distribution problems in the body.
The kidney is a marvel of engineering. Humans have about three to four quarts of circulating blood which course through the kidneys sixty times a day producing forty-five gallons of urine! This dilute urine from filtered blood then moves through kidney tubules where water is absorbed producing concentrated urine. It is this ability to concentrate wastes in a small volume of urine (about half a gallon) that allowed our ancestors to move from the sea to the land and eventually become thoughtful beings and write essays for The Focus.
On a more practical level people often complain when their urine smells. Unless there is incontinence and soiling of clothes this is rarely a sign of disease as long as there aren’t other symptoms such as burning or difficulty urinating. Most of the time urinary odor is due to insufficient fluid intake and the concentration of obligatory waste in very small volumes of urine.
I don’t mean to be crude, but it’s the difference between perfume and cologne or toilette water. There is a much greater effect in the more concentrated liquid. I trust this illustration is helpful and doesn’t offend sensibilities – or stink up our Focus!