Ebenezer Scrooge may be the most memorable character from Charles Dickens' "A Christmas Carol," with his "Bah, humbug!" and stingy ways. But medical sleuths are more interested in the book's biggest unanswered question: What exactly was wrong with Tiny Tim, Bob Cratchit's sickly son?
Online detectives have been debating this question for years, using clues taken from the book to form possible diagnoses.
Internist Dr. Daniel J. Glunk, president-elect of the Pennsylvania Medical Society, has examined all of these theories and determined that many seem to have merit in identifying Tiny Tim's ailment.
We know that Tiny Tim was growing up in London in the mid-1800s, a time when heavy smog lay thick in the air, blocking sunlight.
From Dickens' descriptions of the lad, we know he was very small, used a crutch and was very sick. Because Scrooge was a well-known, well, scrooge, it is clear Cratchit's meager salary was not enough to buy good food and medicine for his son. From the scenes Scrooge sees while being visited by the ghosts, we see Cratchit carrying Tiny Tim from time to time, a possible sign of muscle fatigue. We also learn through Scrooge's time travels that Tiny Tim would soon die.
At the end of the book, readers are led to believe that the pay raise the changed Scrooge gives Bob Cratchit helps to save Tiny Tim.
One theory floating around the Web is that Tiny Tim suffered from renal tubular acidosis (RTA), a kidney disease that makes blood too acidic.
According to Glunk, RTA occurs when the kidneys fail to excrete acids into the urine, cause the acid to build up in the blood. The result can be growth retardation, kidney stones, bone disease and progressive renal failure—symptoms that seem to match some of Tiny Tim's.
"Tiny Tim is small, has malformed limbs and periods of weakness," Glunk said. "These all can be the result of RTA. Plus the fact that Tiny Tim's condition is fatal if left untreated, but reversible if proper medicine is used, helps to guide medical sleuths to RTA."
While 19th century doctors wouldn't have been able to test for the disease or even put a name on it, they did know the symptoms and how to treat them, Glunk said. Frequent doses of alkaline substances would have been given to such patients, which would neutralize the acid in the blood.
Other Internet sleuths have suggested that Tiny Tim suffered vitamin D deficiency, commonly called rickets.
Rickets was a widespread problem in cities with heavy smog that blocked sunlight, a major source of vitamin D.
Without vitamin D, the body can't absorb calcium and has difficulty building and maintaining strong bones. Some signs of rickets include soft bones, muscular weakness, osteoporosis, and joint pain.
"Knowing London's environmental conditions at that time and knowing Tiny Tim used a crutch, it's reasonable to consider this disease, despite the fact that vitamin D wasn't discovered until the early 20th century," Glunk said. "At the time, they could have unknowingly treated this condition through better foods that Scrooge helped to buy."
Of course, it's nearly impossible to say for sure what was ailing Tiny Tim, but that won't keep armchair online physicians from combing for clues to other possible diagnoses.
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Andrea Thompson is an associate editor at Scientific American, where she covers sustainability, energy and the environment. Prior to that, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered Earth science and the environment. She holds a graduate degree in science health and environmental reporting from New York University, as well as a bachelor of science and and masters of science in atmospheric chemistry from the Georgia Institute of Technology.