Are there multiple ways to see whether someone is ill by looking at their blood and if so, what are the ways in which

Question: Are there multiple ways to see whether someone is ill by looking at their blood and if so, what are the ways in which you can tell?
- Keywords:
  blood,
  illness
Asked by anon-236360 to Greg on 12 Mar 2020.
- Greg Heikel answered on 12 Mar 2020:
  
  Yeah there are a lot of different ways. We can measure how much of certain molecules are in the blood to see how well someone’s liver or kidneys are working, as well as a lot of other organs. We can detect and identify bacteria and viruses that are present, we can look at people’s immune systems to see if they’re working as they should and we can detect and analyse some cancers. We also often use the blood to analyse people’s DNA to see if they have any genetic diseases or if they’re more susceptible to certain diseases. These are just a small selection of things, if you’d like any specific examples of tests that we do please let me know 🙂

Question: Are there multiple ways to see whether someone is ill by looking at their blood and if so, what are the ways in which you can tell?