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Diabetes insipidus

Mate huka mimi waimeha

A cross section diagram showing optic nerve and optic chiasm connecting to the hypothalamus of the brain and pituitary gland at the back of the eyeDiabetes insipidus is a rare condition that causes you to pass too much urine and become very thirsty.

A hormone called anti-diuretic hormone (ADH) works on your kidneys to control how much urine you make. ADH is also called arginine vasopressin (AVP) and is made in a part of your brain called the hypothalamus. It's then stored in the pea-sized pituitary gland, which sits below your brain behind your nose.

While the symptoms can be the same, diabetes insipidus is not related to diabetes, which is caused by having high blood glucose (sugar).

There are two types of diabetes insipidus. Cranial diabetes insipidus is when the cause is in your brain. Nephrogenic diabetes insipidus is when the problem is in your kidneys.

Causes of diabetes insipidus

Cranial diabetes insipidus happens if your body doesn't make enough ADH. The commonest causes of this are:

Nephrogenic diabetes insipidus happens if you have enough ADH but your kidneys do not respond to it. This means your kidneys do not save enough water, so you pass lots of urine. It can be hereditary (passed down in families). Other causes of this include:

Symptoms of diabetes insipidus

The symptoms include being very thirsty, particularly wanting to drink cold water, and passing a lot of pale urine (up to six times as much as normal).

Pēpi (babies) or young tamariki (children) may also lose weight, be irritable, have poor growth, have headaches and be constipated.

Diagnosing diabetes insipidus

To diagnose diabetes insipidus, you'll need to have blood and urine tests. You may need to stop drinking any fluid for a time to check if your urine becomes concentrated.

Your health professional may also give you a dose of ADH to see how your kidneys respond.

You might also need an MRI scan of the pituitary region of your brain.

Treating diabetes insipidus

Cranial diabetes insipidus is treated with artificial ADH called desmopressin. You usually take desmopressin as a nasal spray. Sometimes your health professional will prescribe desmopressin as a tablet. The amount of desmopressin you need varies between different people and can change over time.

If you do not take enough desmopressin, you'll get thirsty again and need to pass a lot of urine.

If you take too much desmopressin, your body keeps too much water. This causes your blood sodium to go low. It may make you feel unwell, and you might have nausea and headaches. Severe low sodium can cause confusion.

To prevent this, your doctor may ask you to intermittently (for example, once a week) withhold your desmopressin until you start passing a lot of urine, after which you can take the dose. This is to give your body a chance to get rid of any excess water that it may have accumulated.

Taking other medications can affect your sodium levels and the amount of desmopressin you need. Check with your doctor when starting new medications. You may need to adjust your medication if you become unwell with vomiting or diarrhoea or if you have to have surgery.

Nephrogenic diabetes is harder to treat as ADH doesn't help. Your doctor may suggest stopping any tablets that could be causing the problem (such as lithium) but you shouldn't stop these medications without your doctor's help.

If you have diabetes insipidus, consider wearing a medic alert bracelet or pendant so medical staff know how to treat you in an emergency. Search online for medical bracelets NZ to find medical bracelet suppliers.

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Written by the Department of Endocrinology, Christchurch Hospital. Adapted by HealthInfo clinical advisers. Last reviewed June 2023.


Page reference: 70635

Review key: HIDII-70635