Diabetes insipidus is a rare disease caused by the lack of vasopressin or antidiuretic hormone (ADH) in the part of the brain called hypothalamus, leading to the kidney producing abnormally large volumes of dilute and odourless urine.

Diabetes mellitus, on the other hand, is the more common form of diabetes. Ones with diabetes mellitus have high sugar levels in their blood caused by the body’s inability to process glucose efficiently. This is due to the deficiency of the insulin hormone in the body.


With diabetes insipidus, one will feel exhaustion and thirst due to dehydration. This is due to the excessive urine excreted which deprives one from minerals such as sodium, potassium or calcium.

In diabetes mellitus, the exhaustion is present, although it is due to the shift in blood sugar levels. The high glucose in the blood also causes constant thirst.

Sugar level in urine

Blood glucose levels for diabetes insipidus do not increase and are not present in the urine, but it causes excessive amounts of diluted and odourless urine to be excreted.

Ones with diabetes mellitus have increased blood sugar level and in urine, but with a normal amount of concentrated urine passed out. Ketone will also be present in the urine of diabetes mellitus.

Health changes

Those with diabetes mellitus will experience an increase in blood cholesterol level, as well as excessive hunger due to changing in eating patterns, unlike diabetes insipidus.


Diabetes mellitus is determined by a few blood tests, such as glucose test and glycated haemoglobin tests, whereas diabetes insipidus is measured by urinalysis and fluid deprivation test.


There is no cure for both diabetes mellitus and insipidus, although one can learn to manage them.

Diabetes is a long term disease and will need to be managed with care. At Regency Specialist Hospital, our Diabetes Care Unit is equipped with specialists and supporting healthcare professionals who are ready to help you improve your health condition.

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