Notes

Diabetes Insipidus

Characterized by excessive thirst and urination.Encyclopedia Entry for Diabetes Insipidus :Diabetes insipidus - central. Diabetes insipidus (DI) is an uncommon condition in which the kidneys are unable to prevent the excretion of water. DI is a different disease than diabetes , though both share common symptoms excessive urination and thirst. Central diabetes insipidus is a form of DI that occurs when the body has a lower than normal amount of antidiuretic hormone (ADH). ADH is also called vasopressin. ADH is produced in a part of the brain called the hypothalamus. It is then stored and released from the pituitary gland. This is a small gland at the base of the brain. ADH controls the amount of water excreted in urine. Without ADH, the kidneys do not work properly to keep enough water in the body. The result is a rapid loss of water from the body in the form of dilute urine. This results in the need to drink large amounts of water due to extreme thirst and to make up for excessive water loss in the urine (10 to 15 liters a day). The reduced level of ADH may be caused by damage to the hypothalamus or pituitary gland. This damage may be due to surgery, infection, inflammation, tumor , or injury to the brain. In rare cases, central diabetes insipidus is caused by a genetic problem.Symptoms of central diabetes insipidus include: Increased urine production Excessive thirst Confusion and changes in alertness due to dehydration and higher than normal sodium level in the body, if the person is unable to drink.The health care provider will ask about your medical history and symptoms. Tests that may be ordered include: Blood sodium and osmolarity Desmopressin (DDAVP) challenge MRI of the head Urinalysis Urine concentration Urine output.The cause of the underlying condition will be treated. Vasopressin (desmopressin, DDAVP) is given either as a nasal spray, tablets, or injections. This controls urine output and fluid balance and prevents dehydration. In mild cases, drinking more water may be all that is needed. If the body's thirst control is not working (for example, if the hypothalamus is damaged), a prescription for a certain amount of water intake may also be needed to ensure proper hydration.Outcome depends on the cause. If treated, central diabetes insipidus usually does not cause severe problems or result in early death.Not drinking enough fluids can lead to dehydration and electrolyte imbalance. When taking vasopressin and your body's thirst control is not normal, drinking more fluids than your body needs can cause dangerous electrolyte imbalance.Call your provider if you develop symptoms of central diabetes insipidus. If you have central diabetes insipidus, contact your provider if frequent urination or extreme thirst returns.Many of the cases may not be preventable. Prompt treatment of infections, tumors, and injuries may reduce risk.Central diabetes insipidus; Neurogenic diabetes insipidus.Endocrine glands Endocrine glands.Brimioulle S. Diabetes insipidus.Encyclopedia Entry for Diabetes Insipidus :Diabetes insipidus. During the day, your kidneys filter all your blood many times. Normally, most of the water is reabsorbed, and only a small amount of concentrated urine is excreted. DI occurs when the kidneys cannot concentrate the urine normally, and a large amount of dilute urine is excreted. The amount of water excreted in the urine is controlled by antidiuretic hormone (ADH). ADH is also called vasopressin. ADH is produced in a part of the brain called the hypothalamus. It is then stored and released from the pituitary gland. This is a small gland just below the base of the brain. DI caused by a lack of ADH is called central diabetes insipidus. When DI is caused by a failure of the kidneys to respond to ADH, the condition is called nephrogenic diabetes insipidus. Nephrogenic means related to the kidney. Central DI can be caused by damage to the hypothalamus or pituitary gland as a result of: Genetic problems Head injury Infection Problem with the ADH-producing cells due to an autoimmune disease Loss of blood supply to the pituitary gland Surgery Tumors in or near the pituitary gland Nephrogenic DI involves a defect in the kidneys. As a result, the kidneys do not respond to ADH. Like central DI, nephrogenic DI is very rare. Nephrogenic DI may be caused by: Certain drugs, such as lithium Genetic problems High level of calcium in the body ( hypercalcemia ) Kidney disease, such as polycystic kidney disease.Symptoms of DI include: Excessive thirst that may be intense or uncontrollable, usually with the need to drink large amounts of water or craving for ice water Excessive urine volume Excessive urination, often needing to urinate every hour throughout the day and night.The health care provider will ask about your medical history and symptoms. Tests that may be ordered include: Blood sodium and osmolality Desmopressin (DDAVP) challenge MRI of the head Urinalysis Urine concentration and osmolality Urine output.The cause of the underlying condition will be treated when possible. Central DI may be controlled with vasopressin (desmopressin, DDAVP). You take vasopressin as an injection, a nasal spray, or tablets. If nephrogenic DI is caused by medicine, stopping the medicine may help restore normal kidney function. But after many years of use of some medicines, such as lithium, nephrogenic DI can be permanent. Hereditary nephrogenic DI and lithium-induced nephrogenic DI are treated by drinking enough fluids to match urine output. Medicines that lower urine output also need to be taken. Nephrogenic DI is treated with anti-inflammatory medicines and diuretics (water pills).Outcome depends on the underlying disorder. If treated, DI does not cause severe problems or result in early death.If your body's thirst control is normal and you are able to drink enough fluids, there are no significant effects on body fluid or salt balance. Not drinking enough fluids can lead to dehydration and electrolyte imbalance, which can be very dangerous. If DI is treated with vasopressin and your body's thirst control is not normal, drinking more fluids than your body needs can also cause dangerous electrolyte imbalance.Call your provider if you develop symptoms of DI. If you have DI, contact your provider if frequent urination or extreme thirst returns.Endocrine glands Endocrine glands Osmolality test Osmolality test.Hannon MJ, Thompson CJ. Vasopressin, diabetes insipidus, and the syndrome of inappropriate antidiuresis.