What is Diabetes Insipidus?

Diabetes insipidus is a rare condition that occurs in 1 in 25,000 people. While it can affect people of any age, it’s most common in adults. Diabetes insipidus results when too much water is passed from the body. It occurs when a hormone known as antidiuretic hormone (ADH), or vasopressin, fails to stop the kidneys from producing urine. People with diabetes insipidus urinate frequently and experience excessive thirst.

Types of Diabetes Insipidus

• Central (or neurogenic)
• Dipsogenic
• Nephrogenic
• Gestational

Each type of diabetes insipidus has a different cause.

What Causes Diabetes Insipidus?

Diabetes insipidus is related to the hormone vasopressin. It can be caused when the pituitary gland does not secrete enough of the hormone or fails to produce it at all. Or, it can be caused when the kidneys do not respond normally to vasopressin.

Central/Neurogenic Diabetes Insipidus

This type of diabetes insipidus occurs when damage to the pituitary gland or hypothalamus disrupts the body’s creation, storage or secretion of vasopressin. As a result, the kidneys remove too much fluid from the body and urination increases. The damage to the pituitary gland or hypothalamus that leads to central diabetes insipidus has a number of causes, including:

• Tumors
• Infection
• Inflammation
• Surgery
• Head injury

Dipsogenic Diabetes Insipidus

Dipsogenic diabetes insipidus results when a patient drinks too much fluid. This can be due to damage in the hypothalamus. The high volume of liquid consumed suppresses the secretion of vasopressin and increases urination. Damage to the hypothalamus, which can result in dipsogenic diabetes insipidus, can be caused by:

• Tumors
• Infection
• Inflammation
• Surgery
• Head injury

Some mental illnesses and certain medications are also attributed to this condition.

Nephrogenic Diabetes Insipidus

Nephrogenic diabetes insipidus results when the kidneys fail to respond normally to vasopressin and remove too much fluid from the bloodstream. This leads to an increase in urination, especially at night. Nephrogenic diabetes insipidus may be inherited or may result from one of the following causes:

• Chronic kidney disease
• Medications, especially lithium
• High calcium levels in the blood
• Low potassium levels in the blood
• Blockage of the urinary tract

Gestational Diabetes Insipidus

Gestational diabetes insipidus is extremely rare, occurring in only 2 to 4 of 100,000 pregnancies. This condition develops when an enzyme in the placenta breaks down vasopressin, or when a pregnant woman produces more of a hormone-like chemical called prostaglandin, which makes the kidneys less receptive to vasopressin. Most cases of gestational diabetes insipidus are mild and present no symptoms. The condition usually goes away on its own after childbirth, but may return in a subsequent pregnancy.

Diabetes Insipidus Signs and Symptoms

Signs and symptoms of diabetes insipidus include:

• Excessive thirst
• Large amounts of diluted urine
• Urinating frequently at night
• A strong preference for cold drinks

Diabetes Insipidus Diagnosis

Doctors consider a number of pieces of information and may use different diagnostic tools to make a diabetes insipidus diagnosis. Doctors may make the diagnosis based on the following:

Family medical history

Diabetes insipidus can be inherited. Doctors will inquire about a patient’s family medical history to determine if they are predisposed to the condition.

Physical exam

The doctor will check for signs of dehydration, including very dry skin. Dehydration is a risk with diabetes insipidus.

Urinalysis

This is an examination of the patient’s urine. Patients will collect a urine sample in a special container and medical professionals will examine the specimen in a lab. Medical providers will seek to determine if the urine is concentrated or dilute, which is a symptom of diabetes insipidus. This test can also determine if there is glucose in the urine, which distinguishes between diabetes insipidus and diabetes mellitus. Patients may also be asked to collect their urine over a 24-hour period to determine how much they are producing.

Blood test

Medical professionals will take a sample of blood from a patient and the results will be determined in a lab. Blood tests can measure the level of vasopressin in the blood. They are also used to measure the level of sodium. In some cases, the level of sodium in the blood can be used to determine the type of diabetes insipidus a patient has.

Fluid deprivation test

Fluid deprivation tests measure urine concentration and changes in body weight following a period of fluid restriction. There are two types of fluid deprivation tests, short form and formal. In a short form test, the patient restricts liquids for a specific period of time, produces a urine sample at home and provides it to a medical professional and the sample’s concentration is tested. In a formal test, the patient is monitored over a period of hours until either their blood pressure drops too low, they have a rapid heartbeat when standing, they lose 5% or more of their body weight or their urine concentration increases very slightly in two or three consecutive measurements. The patient’s vasopressin levels, blood sodium and urine concentration are all used to determine if diabetes insipidus is present.

Magnetic resonance imaging

Magnetic resonance imaging (MRI) takes pictures of the body’s organs without the use of X-rays. A technician will perform the procedure and a radiologist will determine the results. MRIs can show issues with the hypothalamus and pituitary gland, which can disrupt the body’s creation and secretion of vasopressin.

Diabetes insipidus complications

Dehydration is the main complication of diabetes insipidus, due to the large amount of fluid loss that is part of the condition. If fluid intake is not greater than the output, dehydration results. Signs of dehydration include:

• Thirst
• Dry skin
• Fatigue
• Sluggishness
• Confusion
• Nausea

Cases of severe dehydration can result in permanent brain damage, seizures and even death.

Diabetes Insipidus Treatment

Central/Neurogenic Diabetes Insipidus

In mild cases of this condition, a patient may just need to increase their water intake. In other cases, a synthetic hormone called desmopressin is the central/neurogenic diabetes insipidus treatment. This medication replaces the missing vasopressin in the body and decreases urination. Indomethacin, which makes vasopressin more available in the body, may also be prescribed.

Nephrogenic Diabetes Insipidus

Sometimes treating the cause can treat nephrogenic diabetes insipidus. This may include making a medication change or balancing the amount of calcium or potassium in a patient’s body. Other times, diuretics are prescribed. They may be combined with aspirin or ibuprofen. These medications reduce urine production and urine volume.

Dipsogenic Diabetes Insipidus

There is currently no effective dipsogenic diabetes insipidus treatment. Sucking on ice chips or sour candies can increase saliva flow and help reduce the urge to drink. Taking a small dose of desmopressin at bedtime can help with frequent urination at night. Initially, the patient’s blood sodium levels will be monitored to prevent them from becoming too low.

Gestational Diabetes Insipidus

Desmopressin is the gestational diabetes insipidus treatment. Unlike vasopressin, the placenta does not destroy desmopressin. Following childbirth, most women will not need to continue to receive treatment.

Patients who are experiencing excessive thirst and frequent urination – especially if the urine is diluted – should talk to their doctor about diabetes insipidus. Those with a family history of the condition should also talk to their doctor. Patients experiencing symptoms of dehydration, including dry skin, fatigue, sluggishness, confusion and nausea should speak with a Baptist Health medical professional about diabetes insipidus.