Clinically reviewed by K Stanley, CDCES, RDN, LD, MSEd, BCADM, MLDE, Diabetes Educator

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 kidney from concentrating urine, which leads to producing too much urine. People with diabetes insipidus urinate frequently and experience excessive thirst.

What Is the Difference Between Diabetes Insipidus and Diabetes Mellitus?

Diabetes insipidus and diabetes mellitus are two forms of a similar disease with distinctly different causes. Diabetes mellitus, the more common of the two, results when the pancreas fails to make enough insulin to convert food into energy. As the body cannot use food for energy, the body breaks down fat and muscle leading to acidification of the blood and a heightened need to urinate. Diabetes insipidus is caused either by a lack of ADH or by the hormone's inability to properly regulate kidney function. What the two forms of diabetes have in common are the symptoms of excessive thirst and urination.

Types of Diabetes Insipidus

Researchers have recognized four types of diabetes insipidus. These are:

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

Each type of diabetes insipidus has a different cause.

What Are the Most Common Causes of 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. It can also be caused by the kidneys not responding normally to vasopressin.

Central (or 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.

Signs and Symptoms

The primary indicators of diabetes insipidus involve urination and thirst. Signs and symptoms include:

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

Risk Factors

The likelihood of developing diabetes insipidus is increased by the following risk factors:

• A family history of diabetes
• Chemical imbalances in the blood, such as low levels of potassium or high levels of calcium
• Taking prescription diuretics, which can stress the kidneys
• A brain injury or surgical procedure

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 percent 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 (MRI)

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.

Treatment

There are a variety of treatments for diabetes insipidus, depending on the type. These range from increasing water consumption to avoid dehydration to several types of medication.

Central (or 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.

What Can I Do to Manage Diabetes Insipidus?

The single most important step that you can take in managing diabetes insipidus is to drink water regularly. By doing this, you lessen the possibility of dehydration. Your physician may also suggest some changes in diet, such as reducing the amount of sodium (salt) in what you eat and drink.

When Should I See a Healthcare Provider for Diabetes Insipidus?

If you are diagnosed with diabetes insipidus, make certain that you schedule regular visits with your physician. He or she will monitor your progress in managing your condition, adjusting your medications or treatment, according to your symptoms and test results.

Why Choose Baptist Health for Your Health Care

Baptist Health is a leading health care provider in Kentucky and Southern Indiana. We offer comprehensive care through our network of medical facilities and affiliated physicians, nurses, technicians, and support personnel. Our endocrinologists are some of the most experienced in the region.