Question

A man has a urine output of 6 to 8 L/day. He presents with hypernatremia, dehydration, and his antidiuretic hormone (ADH) level is very low. Although he has had no intake for 4 hours, there is no change in his polyuria. These are indications of:

Answer 1

It is an indication of Diabetes Insipidus. However because his ADH levels is very low, then it is Central Diabetes Insipidus(CDI) or Neurologic Insipidus.

Generally diabetes insidpidus is a clinical disorder due to disruption of the body electrolyte fluid balance,leading to increase in solute potential of the blood, polyuria and polydipsia. it is caused by infections, tumors, trauma, autoimmune diseases to the pituitary gland .

Specifically Central Diabetes Insipidus (CDI) is due to lack of ADH production in the hypothalamus. Since ADH promotes water re-absorption at the kidneys to increase blood volume,when solute potential of the blood increases during Hypernatremia, lack of ADH leads to increase in blood solute potential, from production of larger quantity of diluted urine -polyuria, and therefore polydipsia(great thirst), which depletes the blood of fluids and therefore rise in solute potential.

The fact that the polyuria remains the same despite no intake for 4hrs,is due to lack of ADH and therefore failure to stimulate re-absorption of water at the collecting duct, thus as the kidney produces urine, this is coming out with no re-absorption of water back to the blood,Therefore large diluted urine will continuously be produced.

Note - the condition is related to diabetes mellitus because of the polyuria, symptoms, it has no other correlation with diabetes mellitus outside this.

Step-by-step explanation:

Answer 2

Diabetes Insipidus

Step-by-step explanation:

Diabetes Insipidus is a rare condition that affects the kidneys ability to prevent excretion of water hence a lot of urine is produced.

This condition is caused by a damage in the pituitary gland or hypothalamus hence affecting the usual production of ADH which is responsible of controlling the amount of water in the urine.

Therefore, a patient who presents polyuria, hypernatremia , dehydration and low levels of ADH is an indication of Diabetes insipidus.