We were interested to read about life with long Covid and our hearts go out to the children described, and all the sufferers of this condition (Childhood, interrupted: 12-year-old Toby’s life with long Covid, 12 June). However, doctors are still debating the causes of long Covid. We are concerned about the science behind the “microclots” hypothesis as a cause of long Covid and have examined it academically.
The evidence base for “microclots” causing long Covid is tenuous to say the least: the research shows these particles are found in normal individuals and other conditions. This makes it unlikely that they are the cause of long Covid. Indeed, the particles are not actually clots; they are small particles of a protein called amyloid, which are not involved in blood clotting.
