An Essential Step Skipped

Suddenly her symptoms took on an entirely different shape. I had been making assumptions about her case based on the fact that the doctors who referred her to our center thought her symptoms were a result of long Covid. But in truth, none of us really knew if she was suffering from long Covid. There is no definitive test that links present symptoms to a Covid infection experienced weeks, months or even years earlier. The first published reports of symptoms that outlasted the viral infection came in April 2020, just months after the virus arrived in the United States. And since then, a wide range of symptoms has emerged. But the links between the symptoms and the hypothesized cause was temporal. There is only the patient’s experience to suggest a connection. But as with so many of the disorders for which there are no definitive tests, this is a diagnosis that can be made only when other possibilities have been ruled out. In seeing this patient, I skipped that essential step.

This was a middle-aged woman who had a racing heart, who became short of breath with any exertion, who was rapidly losing weight — a classic presentation of thyroid-hormone overload, a condition known as hyperthyroidism. This tiny gland located in the neck is part of a complex system that controls body metabolism. When too much thyroid hormone is released, the body’s engine revs as if someone had stepped on the gas and not let up. She had all the symptoms of hyperthyroidism, and I had simply not seen it. I sent her to the lab down the hall from my office. Within hours it was clear that her system was flooded with these hormones.

I called the patient immediately to explain that, despite the positive active-stand test, she probably did not have POTS and that, instead, her thyroid had gone wild. This is usually a result of an autoimmune disorder known as Graves’ disease, in which antibodies bind to thyroid gland receptors, mistake these normal cells for attacking invaders and trigger a near-continuous release of its hormones. Even before the diagnosis of Graves’ was confirmed, the patient was started on a medication to block hormone production.

I have spent the past 20 years writing and thinking about diagnostic errors. And I understand how this one happened. In medicine, most diagnoses are made through a process of recognition. We see something, recognize it and act on what we see. Most of the time we are right. Most of the time. I’ve asked this patient for a photograph to keep on my desk. A reminder, I hope, that the first diagnosis to come to mind can never be the only one considered.

As for the patient, she feels much better since starting these medications. Her heart rate is down, and the basement stairs are getting easier. She tells me she stopped losing weight, but she won’t feel as if she is back to her old self until her cheekbones go back into hiding.

Lisa Sanders, M.D., is a contributing writer for the magazine. Her latest book is “Diagnosis: Solving the Most Baffling Medical Mysteries.” If you have a solved case to share, write her at [email protected].