It happens at least once per week that a family brings their child in with a frustrating problem. The complaints are vague, like mild fever off and on for weeks or months, or headaches or belly pain, or odd rashes. The problem has usually been going on for weeks or months and no doctor has been able to give the family a solid diagnosis. The family asks me: “There has got to be some test to figure this out!”
There is a myth that the sophisticated technology of testing, whether it is blood tests, CT scanning, or MRI scanning, can diagnose all ills. Patients and families believe it, and many doctors also fall into the habit of relying on batteries of tests to help them feel better about their diagnoses.
But this is not true. The vast majority of tests provide us only with a hint that our diagnosis is on the right path. Some tests, particularly CTs and MRIs, give too much information. It happens regularly that we order a CT scan, find something that looks funny, and chase a phantom with further tests. It is not unusual for a doctor and his patient to get caught in what I call the “medical vortex,” where one test leads to another. After thousands and thousands of dollars of painful testing, the doctor finally says “nothing serious is wrong.”
When it comes to making a diagnosis, the old wisdom we all learned in medical school holds true: you make 85% of your diagnoses from taking the medical history alone. As the father of modern medicine, William Osler, said almost a hundred years ago, “listen to the patient, he is telling you his diagnosis.” The next 10% of diagnosis comes from the physical exam. That leaves only 5% of cases where the test makes you go “Ah-hah, so that’s it!” Again, tests mostly just hint.
Thus if you ever have a family member with a medical problem that they just can’t figure out, make sure first that they are asking enough questions. Make sure that the doctor is getting a clear picture of what is going on with the patient. A thorough enough history almost always shows where others have missed a vital clue.
If the doctor starts doing tests, he or she should have a firm idea of how the tests are going to help make the diagnosis, rather than a vague notion that they will shed some light somewhere. Before the tests, the doctor should have listened carefully to your story, asked questions exhaustively, and examined you thoroughly. If so, he or she then probably doesn’t need the tests in the first place!
Do you have a story about missed diagnsosis, testing misadventure, and medical frustration? Click on comments below and tell us.