When investigating a disease, one ought to consider three issues:
1. Disease manifestation.
2. What drives the disease?
3. Treatment objectives.

Medicine postulates that:
1. Diabetes mellitus is manifested by an ongoing rise of blood sugar.  The rising glucose concentration is toxic to tissues (glucose toxicity), and damages small blood vessels (micro-angiopathy).  Blood supply to tissues declines and cells die, which is manifested by peripheral neuropathy, kidney damage and  blindness.
2. Diabetes mellitus is driven by an error of glucose control. Insulin fails to keep  blood glucose at  its normal level, which is known as insulin resistance.
3. Treatment ought to prevent glucose toxicity by keeping  blood  glucose at its normal level.

While disease manifestation are facts observed during  the evolution of diabetes mellitus, the other two issues are interpretations  of the observed facts. They are hypotheses based on the facts.

The main confusion of modern medicine originates from its failure to distinguish between facts and interpretation.  In most patients medicine fails to meet its treatment objectives. Despite treatment, blood glucose rises and patients succumb to glucose toxicity, which indicates that the interpretation  of the observed facts is  false.

The following interpretation is based on  Galen's  principle: "Nothing is done by Nature in vain"   which contradicts medicine’s view that  diabetes mellitus is driven by an error of glucose control.  All along its evolution, diabetes mellitus is controlled by WOB. At any instant WOB adjusts processes so as to minimize the harm of the disease. This process adjustment is called here  WOB solution.  The modern version of Galen's principle  states that at any instant WOB solution is optimal.

Issues 2, and 3 are rephrased as follows:

2. Diabetes mellitus is driven by a rising demand for glucose by the brain . While medicine regards diabetes mellitus as a rising hyperglycemia, here it is regarded as a rising normoglycemia.  The rising blood sugar is vital for  the  brain.
3. The physician has to work out a compromise between WOB demands (rising blood glucose) and the toxic effects high blood glucose. Treatment objectives are to slow down disease progression.

The details are explained in the following articles:

1. Diabetes mellitus
2. What is normoglycemia?
3. Insulin -Yogi

Epilogue

I. You might compare this reasoning with that of cancer. Both are similar. They differ only in their disease specific details. Similar reasoning is applicable to any disease. The framework consists of the three issues mentioned above. The details specifying a disease are parameters of this framework. Together they may serve for a new and consistent classification of diseases.

II. The same reasoning applies to essential hypertension. In the above text replace 'blood sugar' with 'blood pressure', and diabetes with essential hypertension.

Issues 2, and 3 are rephrased as follows:

2. Essential hypertension is driven by a rising demand for glucose by the brain which is supported by raising the blood flow (throughput) through the brain. While medicine regards essential hypertension as a rising hyper-tension, here it is regarded as a rising normo-tension.  The rising blood pressure is vital for  the  brain.
3. The physician has to work out a compromise between WOB demands (rising blood pressure) and the damage to organs caused by elevated blood pressure. Treatment objectives are to slow down disease progression.

This analogy implies that diabetes mellitus and essential hypertension are driven by the same driver.