Diabetes Insipidus Definition When you hear the term "diabetes insipidus," you you may assume it's related to what's commonly known as "sugar" diabetes, or diabetes mellitus. While the disorders share a name and have some common signs, in fact diabetes mellitus (type 1 and type 2) and diabetes insipidus are unrelated. Diabetes insipidus (DI) is a disorder characterized charact erized by intense thirst and by the excretion of large amounts of urine (polyuria). In most cases, it's the result of your body not properly producing, storing or releasing r eleasing a key hormone, but diabetes insipidus can also occur when your kidneys are unable to properly respond to that hormone. Rarely, diabetes insipidus can occur during pregnancy (gestational diabetes insipidus). Effective treatments are ar e available to relieve your thirst and normalize your urine output.
Symptoms The most common signs and symptoms of diabetes insipidus are:
Extreme thirst Excretion of an excessive volume of diluted urine
Depending on the severity of the condition, urine output can range from 2.6 quarts (about 2.5 liters) a day if you have mild diabetes insipidus to 16 quarts (about 15 liters) a day if the t he condition is severe and if you're taking in a lot o f fluids. In comparison, the average urine output for a healthy adult is in the range of 1.6 to 2.6 quarts (about 1.5 to 2.5 liters) a day. Other signs may include needing to get up at night night to urinate (nocturia) and bedwetting. Infants and young children who have diabetes insipidus may have the following signs and symptoms:
Unexplained fussiness or inconsolable crying Unusually wet diapers Fever, vomiting or diarrhea Dry skin with cool extremities Delayed growth Weight loss
When to see a doctor See your doctor immediately if you notice the t he two most common signs of diabetes insipidus: excessive urination and extreme thirst.
Causes Female urinary system
Male urinary system
Normally, your kidneys remove excess body fluids fro m your bloodstream. bloodstream. This fluid waste is stored in your bladder as urine. When your fluid regulat ion system system is working properly, your kidneys make less urine when your body water is decreased, such as through perspiration, in order to conserve fluid. The volume and composition of your body fluids r emain balanced through a combination of oral intake and excretion excret ion in the kidneys. kidneys. The rate rat e of fluid intake is largely governed by thirst, although your habits can increase your intake far a bove the amount necessary. The rate of fluid excreted by your kidneys is greatly influenced by the production of anti-diuretic hormone (ADH), also called vasopressin. Your body makes ADH in the hypothalamus and stores the hormone in your pituitary gland, a small gland located in the base of o f your brain. brain. ADH is released re leased into your bloodstream when necessary. ADH then concentrates the urine by tr iggering the kidney tubules to reabsorb water back into your bloodstream rather t han excreting water into your urine. Diabetes insipidus occurs when this t his system system is disrupted disrupt ed and your body can't regulate how it handles fluids. The way in which your system is disrupted determines which form of diabetes insipidus you have:
Central diabetes insipidus. The cause of central diabetes insipidus is usually damage to the pituitary gland or hypothalamus, most commonly due to surgery, a tumor, illness (such as
meningitis), inflammation or a head injury. In some cases the cause is unknown. This damage disrupts the normal production, storage and release of ADH. Nephrogenic diabetes insipidus. Nephrogenic diabetes insipidus occurs when there's a defect in the kidneys tubules — the structures in your kidneys that cause water to be excreted or reabsorbed. This defect makes your kidneys unable to properly respond to ADH. The defect may be due to an inherited (genetic) disorder or a chronic kidney disorder. Certain drugs, such as lithium and tetracycline, also can cause nephrogenic DI. Gestational diabetes insipidus. Gestational diabetes insipidus occurs only during pregnancy and when an enzyme made by the placenta — the system of blood vessels and other tissue that allows the exchange of nutrients and waste products between a mother and her baby — destroys ADH in the mother.
In about 30 percent of cases of diabetes insipidus, doctors never determine a cause.
Risk factors Nephrogenic diabetes insipidus that's present at or shortly after birth usually has a genetic cause that permanently alters the kidneys' ability to concentrat e the urine. Nephrogenic DI usually affects males, though women can pass the gene on to their children.
Complications Diabetes insipidus can cause your body to retain an inadequate a mount of water to function properly, and you can become dehydrated. Dehydration can cause:
Dry mouth Muscle weakness Low blood pressure (hypotensi ( hypotension) on) Hypernatremia Sunken appearance to your eyes Fever or headache, or both Rapid heart rate Weight loss
Diabetes insipidus can also cause an electrolyte imbalance. Electrolytes are minerals in your blood — such as sodium, sodium, potassium pota ssium and and calcium — that maintain the balance of fluids in your body. Electrolyte imbalance can cause sympto ms, such as headache, fatigue, irritability and muscle pains
Preparing for your appointment You're likely to start by first seeing see ing your family doctor or a general practitioner. practit ioner. However, in some cases when you call to set up an appointment you may be referred immediately to a specialist called an endocrinologist. Because appointments can be brief, and because there's often a lot of ground to cover, it's a good idea to be well prepared for your appointment. Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance. Your doctor may ask you to stop drinking water the night before your test or on the day of your appointment. Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment. Be prepared to answer specific questions about how often you urinate and how much water you drink each day. Write down key personal information, including any major stresses or recent life changes. Make a list of your key medical information, including recent surgical procedures, the names of all medications medicat ions you're you're taking and any other ot her conditions for which you've recently been treated. Your doctor will also want to know about any recent injuries to your head. Take a family member or friend along, if possible. Sometimes it can be difficult to soak up all the informat ion provided to you you during an appointment. Someone who accompanies you may remember something t hat you missed or forgot. Write down questions to ask your doctor.
Prepare a list of questions ahead of your appointment appointment so that t hat you can make the most of your time with your doctor. For diabetes insipidus, some basic questions to ask your doctor include:
What is likely causing my symptoms or condition? Other than the most likely cause, what are possible causes for my symptoms or condition? What kinds of tests do I need now? Is my condition likely temporary or chronic? What is the best course of action? How will you monitor whether my treatment is working? Will I need to make any changes to my diet or lifestyle? Will I still need to drink a lot of water if I'm I 'm on medications? I have these other health conditions. How can I best manage them together? Are there any restrictions that I need to follow? Should I see a specialist? What will w ill that cost, and will my insurance cover seeing a specialist? Is there a generic alternative to the medicine you're prescribing me? Are there any brochures or other printed mater ial that I can ca n take home with me? What Web sites do you recommend visiting?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something. What to expect from your doctor Your doctor is likely to ask you a number of questions. Being ready to answer them
may reserve time to go over any points you want to spend spend more time t ime on. Your doctor may ask:
When did you first begin experiencing e xperiencing symptoms? How much would you say the frequency with which you have to urinate and the amount of urine you produce have increased? How much water do you drink each day? Are you pregnant? Are you currently being treated or have you recently been treated for any other medical conditions? Have you had any recent head injuries or have you had neurosurgery? Has anyone in your family been diagnosed with diabetes insipidus? What, if anything, seems to improve your symptoms? What, if anything, appears to worsen your symptoms? symptoms?
What you can do in the meantime While you're waiting for your appointment, drink until your thirst is relieved, as often as necessary. Avoid activities that might cause dehydrat ion, such as physical physical exertion exert ion or spending time in hot environments.
Tests and diagnosis Your doctor will perform a number of tests test s to diagnose diabetes insipidus, since the signs and symptoms can be caused by a number of conditions, such as diabetes d iabetes mellitus. If the diagnosis of diabetes insipidus is made, your doctor will need to determine which type of diabetes insipidus you have, because the tr eatment is different for each for m of the disease. Some of the tests that doctors commonly commonly use to determine deter mine the type of diabetes insipidus and in some cases, its cause, include:
Water deprivation test. This test helps determine the cause of diabetes insipidus. You'll be asked to stop drinking fluids two to three hours before the test so that your doctor can measure changes in your body weight, urine output and urine composition when fluids are withheld. In some cases your doctor may also measure blood levels of ADH during this test.
The water deprivation test is performed perfor med under close supervision supervision in children and in pregnant women to make sure no more than 5 per cent of body weight is lost during the test.
Urinalysis. Urinalysis is the physical and chemical examination examinat ion of urine. If your urine is less concentrated (meaning the amount of water excreted is high and the salt and waste concentrations are low), it could be due to diabetes insipidus. Magnetic resonance imaging (MRI) scan. An MRI of the head is a noninvasive procedure that uses powerful magnets and radio waves to construct detailed pictures of brain tissues. Your doctor may want to perform an MRI to look for abnormalities in or near the pituitary gland.
Family history If your doctor suspects an inherited form of diabetes insipidus, he or she will look at your family history of polyuria po lyuria and may suggest genetic screening. scree ning.
Treatments and drugs Treatment of diabetes insipidus depends on what form of the condition you have, so your doctor will want to determine deter mine which form of DI is present before beginning treatment. Following are the treatment trea tment options for the most common types of diabetes insipidus:
Central diabetes insipidus. Because the cause of this form of diabetes insipidus is a lack of anti-diuretic hormone (ADH), tr eatment is usually with a synthetic hormone called desmopressin. You can take desmopressin as a nasal spray, oral tablets or by injection. The synthetic hor mone will eliminate the increase in urination. For most people with centra l DI, desmopressin is a safe and effective treatment. tr eatment. If the condition is caused by an abnormality in the pituitary gland or hypothalamus (such as a tumor), your doctor will first tr eat the abnormality.
If you have central DI, be sure to replace any fluid that you do lose; however, while you're taking desmopressin, drink fluids or water only when you're thirsty. This is because the drug prevents excess water excret ion, which means your kidneys are making less urine and are less responsive to changes in body fluids. In mild cases of central DI, increased water intake may be all that t hat you need. Your doctor may suggest a certain amount of water intake — usually more more than 2.6 quarts (about 2.5 liters) a day — to ensure proper hydration.
t he result of your kidneys Nephrogenic diabetes insipidus. This condition is the not properly responding to ADH, so desmopressin is not a treatment treat ment option. Instead your doctor may prescribe a low-salt diet to help r educe the amount of urine your kidneys make. You'll also need to be sure to drink enough water to avoid dehydration. The drug hydrochlorot hydrochlorothiazide, hiazide, used alone or with other medications, may improve symptoms. Although hydrochlorothiazide hydrochlorothiazide is a diuretic diuret ic (usually used to increase urine output), in some cases it can ca n reduce urine output for people with nephrogenic DI. If symptoms from nephrogenic diabetes insipidus are due to medications you're taking, stopping these medicines may help; however, don't stop taking any medication without talking with your doctor first.
gestat ional DI is Gestational diabetes insipidus. Treatment for most cases of gestational with the synthetic hormone desmopressin. In rare cases, an abnormality in the thirst mechanism causes gestational DI. In these rare cases, doctors don't don't prescribe desmopressin.
Lifestyle and home remedies If you have diabetes insipidus, it's important to prevent dehydration. Your doctor will suggest how much fluid you may need to take in to avoid becoming dehydrated. Be sure to carry water with you wherever you go, in case you're in a situation where water or fluids aren't readily re adily available. Wear a medical alert bracelet or carry a medical alert card in your wallet so that if you have a medical emergency, a health hea lth care professional will recognize immediately your need for special treatment.
