Once upon a time people only went to the doctor when they felt sick. For most of human existence there was not much the doctor could actually do when you got there. Yet somehow the human race managed to get through to the second half of the twentieth century when things changed completely.

As technology advanced exponentially we developed a range of treatments so that conditions, which used to be fatal could now be cured. Penicillin as a treatment for bacterial infections is the best example of this. Surgical techniques also improved beyond measure, as did the safety of anaesthesia.

Coupled with this came the advance of medical tests so that disease could be found earlier. People were encouraged to go to the doctor early, as the sooner problems were detected the better. This makes good sense. It is better to treat most conditions in their early rather than advanced stages.

Then it all went one step further.

Medicine started treating people who did not actually have symptoms but had risk factors. High cholesterol and high blood pressure are examples of this. You only know you have it if you are tested or measured (some people do have symptoms with high blood pressure but only when it is very high).

The last step was to launch mass screening programs so people didn’t even need to go to the doctor for testing.

The theory is that the more we find at an early stage the better for all concerned.

Except that nothing in medicine is a straight line. If a little is good more may be better, but a lot more is not necessarily better and can be worse. Every drug has an effective dose and then there is potential overdose. We all know that an overdose is a problem and can be a serious one too.

Collectively we are overdosing on tests. And whilst the logic that finding things early seems flawless the reality is that it is flawed. There are a number of reasons for this.

1. Not everything that is found is actually a sign of disease. Incidentalomas are the medical term for incidental findings, which have no clinical significance, but if unearthed end up needing further tests to prove that this is the case. More tests can mean both more expense but also worry and the risk of complications or side effects.

2. Our capacity to interpret has exceeded our ability to find. It is likely that every person has a cancer cell somewhere in their body on any given day but they will never manifest as cancers. Over 30% of breast cancers found on screening represent over diagnosis. This is where the cancer, which is found, would not have manifested in the persons life or caused them any health problems. Around 50 men have prostate cancer surgery for every one who has their life extended or improved.

3. The lowering of thresholds brings more people into the “disease” category. Every time normal levels for cholesterol, blood pressure or blood sugar are lowered a whole new group of people can be reclassified as having a condition and hence a candidate for treatment.

4. Historically treatment benefits were determined on more severe cases. For example a person with a blood pressure of 200 gets much more benefit from lowering the pressure than someone with a pressure of 145. Yet both are classed as hypertensive and in equal need of treatment.

5. The reclassifying of normal body processes as a disease. Menopause  (a normal part of life) was a classic example of this. Osteoporosis is another. Bones get “thinner” for many as we age. This is not a disease. Mental health diagnoses (like oppositional defiance disorder) is a whole article in itself.

6. Treatments can do harm. Surgery can have complications and medications have side effects. These can be justified where benefit outweighs risk. The wider we cast the net and the milder and less significant the “abnormalities” the greater the chances of harm outweighing benefit. The prostate example above is compounded by the fact that a reasonable number of men may end up incontinent and/or impotent post surgery. This is acceptable if you might live for an extra ten years but not if your life is neither extended nor enhanced. Elderly people treated for marginally high blood pressure may fall and sustain injuries. This is potentially far worse than having a slightly elevated blood pressure.

This is not an argument against treating people who need it and who would benefit. It is against the reclassifying of well people as diseased and the notion that everyone has something wrong with them until they have been screened to prove otherwise.

Early diagnosis is not the same as over-diagnosis. The medical industrial complex is over–reaching its mark and doing collateral damage to people who were well till they got drawn into the net. Nine American Colleges have produced a website called Choosing Wisely making the case for not doing certain procedures tests or treatments routinely. This problem is not confined to the USA.

Rather than see health as an absence of disease we need to see health as the presence of wellbeing. This is in the hands of the individual on a daily basis and is about how they eat, exercise, rest, and manage their stress and the other basics of health.

The best way not to be sick is to be healthy.

Joe Kosterich is a physician in Australia who blogs at Dr. Joe Today.