What is Diabetes Insipidus?
Diabetes insipidus is a disorder of the endocrine system relating to a hormone called antidiuretic hormone (ADH). Another name for ADH is vasopressin.
Diabetes insipidus is very different to the better known diabetes mellitus (insulin- or non-insulin-dependent diabetes).
ADH is produced by the body in a part of the brain called the hypothalamus and is stored in a gland at the base of the brain called the pituitary gland. ADH is secreted from the pituitary gland into the blood stream where it acts on the kidney to make it conserve fluid. In diabetes insipidus there is a lack of ADH which means that the kidney does not conserve fluid - this results in the loss of large volumes of urine, causing various problems.
There are two types of diabetes insipidus:
- central (neurogenic) - caused by a condition of the hypothalamus or pituitary gland, meaning that not enough ADH is produced
- nephrogenic - caused by the kidney failing to respond correctly to ADH
With proper treatment, the long-term prognosis for diabetes insipidus is good.
What are the symptoms of diabetes insipidus?
The main symptom is a large increase in urine output from the normal average of 1.5 litres a day to as much as 18 litres daily. This excessive fluid loss causes thirst and dehydration and can lead to low blood pressure. Similar symptoms occur in diabetes mellitus. However, in diabetes mellitus the urine contains sugar - this is not the case in diabetes insipidus.
Other symptoms may include loss of appetite, headaches, loss of strength and weight, and muscular pains. The symptoms of extreme thirst and excessive fluid output throughout the day and night can also cause related problems such as sleep deprivation and may interfere with normal daily activities.
What are the causes of diabetes insipidus?
Central diabetes insipidus is caused by a disease or abnormality of either the hypothalamus or the pituitary gland, for example: autoimmune disease where the body destroys its own pituitary gland; infections such as meningitis, which can cause damage to the pituitary gland; tumours of the hypothalamus or pituitary gland which are not necessarily malignant (cancerous) but can destroy part of the area; injury or trauma in the region of the hypothalamus or pituitary gland; or inherited disorders of the pituitary gland.
Nephrogenic diabetes insipidus can be caused by various renal diseases or, very rarely, by a sex-linked, hereditary condition present at birth.
What treatment is available?
Treatment for diabetes insipidus involves the replacement of ADH. Desmopressin is a synthetic form of ADH and can be given either as an injection or as tablets (eg, DDAVP®) or an oral solution. It can also be given in the form of a nasal spray (eg, DDAVP®, Desmospray®).
Desmopressin nasal sprays may also be used in the diagnosis of diabetes insipidus.
Further information available from:
The Pituitary Foundation
86 Colston Street
Helpline: 0117 370 1320 (Monday to Friday 10am-4pm) or firstname.lastname@example.org
Fact sheet provided by MIMS
Date last reviewed: October 2016