What Is Diabetes Insipidus?

What Is Diabetes Insipidus?

Diabetes insipidus is a disease characterized by excessive urination, excessive thirst and drinking excessive amounts of water.

Frequent urination (especially at night) and bedwetting are its most important symptoms. The urine is pale and colorless, with low concentration. Although the symptoms are similar, it is completely different from diabetes mellitus (sugar diabetes). Their causes and treatments are not alike.

There are two main types of diabetes insipidus.

The most common type develops as a result of a deficiency of a hormone called vasopressin. This type develops due to damage to the hypothalamus, where vasopressin is synthesized; the pituitary stalk, through which it is transported; and the posterior pituitary, from which it is released. Vasopressin (antidiuretic hormone) is normally synthesized in nerve cells in the anterior hypothalamus; it travels through the pituitary stalk to the posterior pituitary, where it is stored. Under normal conditions, it acts on the kidneys to concentrate the urine. This type is called pituitary (central or neurogenic) diabetes insipidus. The hypothalamus, pituitary stalk and posterior pituitary may have been damaged by tumors, infections, head trauma and infiltrative diseases, or hormone release may be inadequate from birth. In about half of cases, no cause is found. The pituitary gland is imaged with magnetic resonance imaging (MRI) to try to find the cause.

In treatment, symptoms and signs disappear with the use of desmopressin (DDAVP), a synthetic substance similar to vasopressin. It may rarely resolve on its own, but a complete cure is usually not possible.

Sometimes anterior pituitary hormone disorders may also accompany it. Rarely, it can develop during pregnancy.

The other form of diabetes insipidus is “nephrogenic diabetes insipidus.” The kidneys do not respond to vasopressin (antidiuretic hormone). This disease is caused by certain kidney diseases and medications. Rarely, it can be congenital. It does not respond to desmopressin. A complete cure is not possible. However, some supportive medications can partially improve the symptoms and signs.

Diabetes insipidus must be distinguished from primary polydipsia. Primary polydipsia is most often due to psychogenic causes (drinking excessive amounts of water). Sometimes brain diseases also cause primary polydipsia. It is difficult to treat. Excessive water intake must be prevented.

What Does Excessive Urination Mean?

It means passing 2.5–3 liters of urine or more per day.

Does Pituitary DI Cause Only Excessive Urination, Excessive Thirst and Water Drinking?

As long as the patient is conscious, it is not dangerous because they can easily drink water. If consciousness is lost, the patient becomes dehydrated due to excessive urination and may die. The patient should therefore carry an ID card or bracelet showing their diagnosis for emergencies. This way, the doctor can easily recognize the urgent need for water.