Diabetes insipidus is a condition where the body loses too much fluid through urination, causing a significant risk of dangerous dehydration as well as a range of other illnesses and conditions.
It is a rare disorder affecting the regulation of body fluid levels.
People with diabetes insipidus produce excessive amounts of urine, resulting in frequent urination and thirst. However, the underlying cause of these two symptoms differs from types 1 and 2 diabetes.
The disease takes two main forms: Mephrogenic diabetes insipidus and central or neurogenic diabetes insipidus.
Central diabetes insipidus occurs when the pituitary gland fails to secrete the hormone vasopressin, which regulates bodily fluids. In nephrogenic diabetes insipidus, vasopressin secretion is normal, but the kidneys do not correctly respond to the hormone.
Diabetes insipidus affects roughly 1 in every 25,000 people in the United States.
Fast facts on diabetes insipidus
Here are some key points about diabetes insipidus. More detail and supporting information is in the body of this article.
Diabetes insipidus is a condition where the body fails to properly control water balance, resulting in excessive urination.
Excessive production of dilute urine in diabetes insipidus is often accompanied by increased thirst and high water intake.
Diabetes insipidus can result in dangerous dehydration if a person does not increase their water intake, such as when a patient cannot communicate their thirst or help themselves.
As diabetes insipidus is not a common condition, diagnosis involves the exclusion of other common possible explanations for symptoms.
The need to urinate in large volumes can wake people with diabetes insipidus.
The main symptom of all cases of diabetes insipidus is frequently needing to pass high volumes of diluted urine.
The second most common symptom is polydipsia, or excessive thirst.
In this case, results from the loss of water through urine. The thirst prompts the person with diabetes insipidus to drink large volumes of water.
The need to urinate can disturb sleep. The volume of urine passed each day can be anywhere between 3 liters and 20 liters, and up to 30 liters in cases of central diabetes insipidus.
Another secondary symptom is dehydration due to the loss of water, especially in children who may not be able to communicate their thirst. Children may become listless and feverish, experience vomiting and diarrhea, and may show delayed growth.
Other people unable to help themselves to water, such as people with dementia, are also at risk of dehydration.
Extreme dehydration can lead to hypernatremia, a condition in which the sodium concentration of the serum in the blood becomes very high due to low water retention. The cells of the body also lose water.
Hypernatremia can lead to neurological symptoms, such as overactivity in the brain and nerve muscles, confusion, seizures, or even coma.
Without treatment, central diabetes inspidus can lead to permanent kidney damage. In nephrogenic DI, serious complications are rare, so long as water intake is sufficient.
Diabetes insipidus becomes a serious problem only for people who cannot replace the fluid that is lost in the urine. Access to water and other fluids makes the condition manageable.
If there is a treatable underlying cause of the high urine output, such as diabetes mellitus or drug use, addressing this should help resolve the diabetes insipidus.
For central and pregnancy-related diabetes insipidus, drug treatment can correct the fluid imbalance by replacing vasopressin. For nephrogenic diabetes insipidus, the kidneys will require treatment.
Vasopressin hormone replacement uses a synthetic analog of vasopressin called desmopressin.
The drug is available as a nasal spray, injection, or tablet, and is taken when needed.
Care should be taken not to overdose, as this can lead to excessive water retention and, in rare, severe cases, hyponatremia and fatal water intoxication.
The drug is otherwise generally safe when used at appropriate dosages, with few side effects. It is, however, not effective if diabetes insipidus occurs as a result of kidney dysfunction.
Mild cases of central diabetes insipidus may not need hormone replacement and can be managed through increased water intake.
Nephrogenic diabetes insipidus treatments may include:
anti-inflammatory medicines, such as non-steroidal anti-inflammatory drugs (NSAIDS)
diuretics, such as amiloride and hydrochlorothiazide
reducing sodium intake and increasing water intake
A doctor may also advise a low-salt diet, and a person with diabetes insipidus may be referred to a nutritionist to organize a diet plan.
Reducing caffeine and protein intake and removing processed foods from the diet can be effective steps to controlling water retention, as well as consuming foods with high water content, such as melons.
Both types of diabetes insipidus are linked to a hormone called vasopressin but occur in different ways.
Vasopressin promotes water retention in the kidneys. This also keeps blood pressure at a healthy level.
The main symptom, excessive urine output, can have other causes. These would usually be ruled out before making a diagnosis of diabetes insipidus.
For example, undiagnosed or poorly managed diabetes mellitus can cause frequent urination.
Central diabetes insipidus
Central diabetes insipidus is caused by reduced or absent levels of vasopressin.
The condition can be present from birth, or primary. Secondary central diabetes insipidus is acquired later in life.