Clifford Marks and Trevor Pour write in The New Yorker that COVID-19 has been shown to damage multiple organ systems, including the lungs, the heart, the kidneys, and the brain.
We think of covid-19 as a disease of the respiratory tract, they write. When future generations look back on this pandemic, its iconic symbol will probably be the ventilator. But, although respiratory problems are at the core of the disease, covid-19 has revealed itself to be more than a straightforward viral pneumonia. Doctors around the world—including in the emergency department where we work, at Mount Sinai Hospital, in Manhattan—have learned the hard way that the coronavirus doesn’t confine its ravages to the lungs. covid-19 can push kidneys into failure, send the body’s immune system into catastrophic overdrive, and cause blood clots that impede circulation to the lungs, heart, or brain. It’s a disease of remarkable complexity, which even the most experienced doctors are struggling to understand.
On blogs, podcasts, and #medtwitter, members of the medical community have been trading stories and theories about covid-19’s intricacies. Often, their conversation has followed the methodology of critical-care doctors. Physicians who work in I.C.U.s tend to talk not about symptoms or diseases—chest pain, diabetes—but about organ systems, which can malfunction and interact in complex ways. System by system, a picture of covid-19 is emerging. Clarifying it may mean the difference between life and death for thousands of people in the months to come.
The shortness of breath that’s most characteristic of covid-19 is reasonably well understood. It originates in the gossamer air sacs of the lungs, called alveoli, where blood and air are separated by such thin membranes that oxygen and carbon dioxide can pass into and out of the bloodstream, respectively. Between them, the lungs have somewhere in the neighborhood of six hundred million alveoli. Severe covid-19 causes many of them to either collapse or fill with fluid. The virus attacks the cells lining the alveoli; our overactive immune systems, in trying to fight the virus, may be damaging them as well. The result is that not enough oxygen gets into the blood.