Lets take an analogy to understand the way modern medicine deals with health. In the health spectrum, say it ranges between 0-100 with 100% being the ultimate state of health. Lets say a disease manifests only when health % falls below 30. Therefore only a person below 30% is considered ill and treated until the health level goes above 30 to say about 40-50 where he can once again function in society normally. This person may consider a range of 40-50 his normal baseline state. In my case, this maybe 70-80 etc. There can be huge differences in what we call normal. This analogy is actually a gross simplification to convey my basic point.
We can gradually increase the level of complexity of this analogy and imagine a spectrum analyzer of an audio system as the different hormone balances in the body. In some people, this may work much more synchronously than others etc.
The disease stage is like reaching the red in your engine’s pedometer, but there have been factors that have lead to it and these factors are very often ignored unless the correlation is gross enough. The body is treated like a machine and its parts are treated in the same way a mechanic would work on a car.