Question: How do you find all of a disease's effects and/or symptoms?

Alex Holmes answered on 11 Jun 2020:

Oh this is a really interesting question!!

The simple answer is we ask enough people with the disease how they feel and note down as many effects and symptoms as we can until we have a pretty long list and an idea of how common certain ones are like 50% of the people we asked might have a rash, or 2% might have a headache to do with the disease. Sometimes the “asking” takes place after the person has died, like in dementia research it’s been really valuable to look at brains and see if there are any changes in it (which you can’t easily do on alive people).

The more complicated answer: it’s really difficult to find them ALL. Even now for a lot of diseases and syndromes we’re still working out what all the effects and symptoms are, this is because some are really rare, or some are only found in certain groups or more often in certain groups. For example, the way that autism shows is thought to be different between boys and girls, but for a long time a lot of study was done mostly on boys so some of the effects seen in girls weren’t known until scientists and doctors realised they were missing out on some data!