Question: How do people know how to cure life-threatening diseases without doing trial and error?

Lilian Hunt answered on 11 Mar 2014:

Really we don’t. Science is a lot of trial and error with educated guesses to decide what to do next. If someone has a life threatening disease we are likely to put a lot of time and effort into studying possible cures before we attempt anything on the person suffering from the disease. This will include making new drugs and testing them to see what they react with, then based on that we change them slightly and see if they work better at what we are trying to get them to do. So that whole process is trial and error! Then when we have something we think might work, we have to test it to see if it’s safe in humans. This involves some testing on animals and then if it passes that step, we test really small doses on humans to check that it isn’t harmful. You might have heard of people with life-threatening diseases taking part in trials of new drugs and treatments to cure them. These people volunteer to test the cure as they often know they will die or suffer without it. If it works, brilliant! If it doesn’t, at least we know it won’t necessarily damage them and we can start looking for something else.