Diabetes insipidus

Overview

Diabetes insipidus (die-uh-BEE-teze in-SIP-uh-dus) is a condition that causes the fluids in the body to get out of balance. Then the body makes and passes large amounts of urine. The condition also causes great thirst even after drinking something.

Depending on the cause, diabetes insipidus also is called arginine vasopressin (AVP) deficiency or resistance.

Diabetes insipidus is not linked to diabetes mellitus, also called type 1 and type 2 diabetes. Diabetes mellitus involves high blood sugar levels, which may cause the body to make too much urine. Diabetes insipidus is not common. Diabetes mellitus is common and often simply called diabetes.

There's no cure for diabetes insipidus. But treatment can ease its symptoms. Easing symptoms includes relieving thirst, lessening the amount of urine the body makes and preventing loss of too much body fluid, called dehydration.

Causes

In diabetes insipidus, the body can't balance fluid levels. The cause depends on the type of diabetes insipidus, also called arginine vasopressin (AVP) deficiency or resistance.

How the kidneys work

The kidneys filter fluid in the blood to remove waste. The kidneys return most of that fluid to the bloodstream. The waste and a small amount of fluid leave the kidneys as urine. Urine leaves the body after it's briefly stored in the bladder.

The kidneys need a hormone called antidiuretic hormone (ADH) to put the filtered fluid back into the bloodstream. The hormone also is called arginine vasopressin (AVP).

ADH comes from a part of the brain called the hypothalamus. The pituitary gland, a small gland at the base of the brain, stores the ADH and lets it out when needed. ADH travels to the kidneys to help the kidneys keep more fluid in the blood and put less fluid in the urine.

Conditions that cause the brain to make too little ADH or that block the effect of ADH cause the body to make too much urine. Kidney conditions that change how the kidney responds to ADH also can cause too much urine.

Types of diabetes insipidus

Types of diabetes insipidus include:

• Central diabetes insipidus. Damage to the pituitary gland or hypothalamus from surgery, a tumor, a head injury or an illness can cause central diabetes insipidus. That damage affects the making, storage and release of ADH. Central diabetes insipidus also is called arginine vasopressin (AVP) deficiency.

  A condition passed down in families, called inherited, may cause central diabetes insipidus too. So can an autoimmune reaction that causes the body's immune system to damage by mistake the cells that make ADH.

• Nephrogenic diabetes insipidus. Also called arginine vasopressin (AVP) resistance, this happens when the kidneys can't respond to ADH. That issue may be due to a condition passed down in families, called inherited. Certain medicines, including lithium and antiviral medicines such as foscarnet (Foscavir), also can cause the condition. Low levels of potassium in the blood, called hypokalemia, also cause it. It can also be caused by high levels of calcium in the blood, called hypercalcemia. It can also be due to a blocked urinary tract or a urinary tract infection.
• Gestational diabetes insipidus. This rare form of diabetes insipidus happens only during pregnancy. It happens when the placenta makes an enzyme that destroys ADH. The placenta is the organ that grows during pregnancy to give oxygen and nutrients to an unborn baby, also called a fetus.

Sometimes, healthcare professionals can't find a clear cause of diabetes insipidus. Repeated testing over time may help find a cause.

Complications

Dehydration

Diabetes insipidus, also called arginine vasopressin (AVP) deficiency or resistance, may lead to dehydration. That happens when the body loses too much fluid. Dehydration can cause:

• Dry mouth.
• Thirst.
• Extreme tiredness.
• Dizziness.
• Lightheadedness.
• Fainting.
• Upset stomach.

Electrolyte imbalance

Diabetes insipidus can change the levels of minerals in the blood that keep the body's fluids balanced. Those minerals, called electrolytes, include sodium and potassium. Symptoms of an electrolyte imbalance may include:

• Weakness.
• Upset stomach.
• Vomiting.
• Loss of appetite.
• Not thinking clearly.

Treatment

If you have mild diabetes insipidus, drinking more water to keep from getting dehydrated may be all you need. For other types of diabetes insipidus, also called arginine vasopressin (AVP) deficiency or resistance, treatment most often depends on the type.

• Central diabetes insipidus, also called AVP deficiency. If an issue in the pituitary gland or hypothalamus, such as a tumor, is the cause, the treatment first aims to treat the cause.

  If you need other treatment, you may get a lab-made hormone called desmopressin (DDAVP). This medicine replaces the missing ADH and lessens the amount of urine the body makes. Desmopressin comes as a pill or nasal spray. If you're in a hospital, you may get it through a vein in your arm.

  With central diabetes insipidus, it's likely that your body still makes some ADH. But the amount can change from day to day. That means the amount of desmopressin that you need also may change.

  Taking more desmopressin than you need can cause your body to hold water. Sometimes, it may cause low sodium levels in the blood that can be serious. Talk with your healthcare professional about how and when to adjust the amount of desmopressin you take.

• Nephrogenic diabetes insipidus, also called AVP resistance. Because the kidneys don't respond well to ADH in this form of diabetes insipidus, desmopressin won't help. Instead, your healthcare professional may tell you to drink plenty of fluid. You also may need to eat a low-salt, low-protein diet to lessen the amount of urine your kidneys make.

  Treatment with hydrochlorothiazide (Microzide) may ease your symptoms. Hydrochlorothiazide is a diuretic, which causes the body to make more urine. But it can lessen urine output for some people with nephrogenic diabetes insipidus.

  If your symptoms are due to medicines you take, stopping those medicines may help. But talk with your healthcare professional before you stop any medicine.

• Gestational diabetes insipidus. Treatment for gestational diabetes insipidus involves taking the lab-made hormone desmopressin.

Preparing for an appointment

You're likely to first see your main healthcare professional, who may send you to a specialist who treats hormone issues, called an endocrinologist.

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do before you go. You may need to stop drinking water the night before the appointment. But do so only if your healthcare professional asks you to.

Take a family member or friend to the appointment if possible. Someone who goes with you can help you remember what your healthcare team tells you.

Make a list of:

• Your symptoms and when they began. Include any that don't seem linked to the reason for your appointment. Be ready to answer questions about how often you urinate and how much water you drink each day.
• Key personal information, including any major stresses or recent life changes.
• Key medical information, including recent surgeries, conditions for which you've recently been treated and recent head injuries.
• All vitamins, minerals and other supplements you take, including dosages.
• Questions to ask your healthcare professional.

For diabetes insipidus, some basic questions to ask include:

• What's the most likely cause of my symptoms?
• What tests do I need?
• Will I always have this condition?
• What treatments are there? Which do you suggest for me?
• How will we know whether my treatment is working?
• Will I need to make changes to my diet or lifestyle?
• Will I still need to drink a lot of water if I'm taking medicines?
• I have other health conditions. How can I best manage these conditions together?
• Are there brochures or other information I can take home? What websites do you suggest?

What to expect from your doctor

Your healthcare professional is likely to ask you questions, including:

• How much more are you urinating than usual?
• How much water do you drink each day?
• Do you get up at night to urinate and drink water?
• Are you pregnant?
• Have you had a recent head injury, or have you had brain surgery?
• Has anyone in your family been diagnosed with diabetes insipidus?
• What, if anything, makes your symptoms better or worse?

What you can do in the meantime

While you wait for your appointment, drink enough to ease your thirst. Don't do anything that might cause water loss. This includes exercise, hard physical work or spending time in the heat.