A pulmonologist who’s recovering from coronavirus describes what it feels like to survive COVID-19’s dreaded ‘cytokine storm’

Of all the possible compounding effects of COVID-19, the disease caused by the novel coronavirus, the cytokine storm is one of the most feared. An immune system overreaction in which the body is flooded with the eponymous signaling molecules, those who suffer a cytokine storm are at risk of dying at the hand of their own immune system, as an indirect effect of the virus they are fighting.

This is the opposite of how we think of our immune system working: if we have a good, strong immune system, we should be safe from the novel coronavirus, right? Unfortunately in this case, too much of a good thing is not a good thing. This is true beyond the example of the cytokine storm, as there are other diseases, often milder ones, caused by a misbehaving immune system; lupus, allergic reactions and celiac disease are all examples of overactive immune responses.

The cytokine storm affects a substantial number of severe COVID-19 patient, enough that it has become the subject of a subset of medical research into COVID-19. Those unlucky enough to experience a cytokine storm will feel cytokines, the immune system helper cells, flood their bodies and especially their lungs as their immune system struggles to fight off the invading virus and the dead lung cells it produces en masse. The overreaction results in the immune system building up too many of these kinds of cells, which can lead to respiratory distress or bacterial pneumonia and ultimately death. Continue reading.