DIABETES INSIPIDUS
What is Diabetes Insipidus?
Most people with diabetes insipidus have kidneys that don't concentrate urine very well. This is characterized by excretion of large amounts of diluted urine, which disrupts your body's water regulation. To make up for lost water, you may feel the need to drink large amounts of water. You are likely to urinate frequently, even at night, which can disrupt sleep or, on occasion, cause bedwetting. Because of the excretion of abnormally large volumes of diluted urine, you may quickly become dehydrated if you do not drink enough water. People with diabetes insipidus are thirsty all the time. Children with DI may be irritable or listless and, in some cases, may have fever, vomiting, or diarrhea.
Damage to the pituitary gland can be caused by different diseases as well as by head injuries, neurosurgery, or genetic disorders. To treat the resulting ADH deficiency, a synthetic hormone called desmopressin can be taken by an injection, a nasal spray, or a pill. While taking desmopressin, you should drink fluids or water only when you are thirsty and not at other times. This is because the drug prevents water excretion and water can build up now that your kidneys are making less urine and are less responsive to changes in body fluids.
What causes Diabetes Insipidus?
The two things that cause
diabetes insipidus are related to a hormone called ADH (Antidiuretic Hormone). In some cases, the part of the brain called the
hypothalamus doesn't make enough ADH),
which your body needs to work right. In other people, the kidneys don't
work with this hormone the way they should.
The kidneys' ability to respond to ADH can be impaired by drugs (like lithium, for example) and by chronic disorders including polycystic kidney disease, sickle cell disease, kidney failure, partial blockage of the ureters, and inherited genetic disorders. Sometimes the cause of nephrogenic DI is never discovered.
Desmopressin will not work for this form of DI. Instead, you
may be given a drug called hydrochlorothiazide (also called
HCTZ) or indomethacin. HCTZ is sometimes combined with amiloride.
Again, you should drink fluids only when you are thirsty and
not at other times.
Most people with diabetes insipidus get it after an injury to the head or after brain surgery. Some people with diabetes insipidus have a brain tumor. Sometimes it runs in families. About 25% of the time, doctors can't find any reason for it.
