Diabetes Insipidus
Diabetes insipidus (DI) is a disease characterized by excretion of large amounts of severely diluted urine, which cannot be reduced when fluid intake is reduced. It denotes inability of the kidney to concentrate urine. DI is caused by a deficiency of antidiuretic hormone (ADH), also known as vasopressin, or by an insensitivity of the kidneys to that hormone. It can also be induced iatrogenically by the diuretic conivaptan.
• Diabetes Insipidus versus Diabetes Mellitus
• Normal Fluid Regulation in the Body
• Central DI
• Nephrogenic DI
• Dipsogenic DI
• Gestational DI
• Diagnosis
• For More Information
Diabetes insipidus (DI) causes frequent urination. The large volume of urine is diluted, mostly water. To make up for lost water, you may feel the need to drink large amounts. 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 dilute urine, you may quickly become dehydrated if you do not drink enough water. Children with DI may be irritable or listless and may have fever, vomiting, or diarrhea. In its clinically significant forms, DI is a rare disease
Diabetes insipidus (DI) causes frequent urination. You become extremely thirsty, so you drink. Then you urinate. This cycle can keep you from sleeping or even make you wet the bed. Your body produces big volumes of urine that are almost all water.
DI is different from diabetes mellitus (DM), which involves insulin problems and high blood sugar. The symptoms can be similar; however, DI is related to how your kidneys handle fluids. It's much less common than DM. Urine and blood tests can show which one you have.
Diabetes Insipidus versus Diabetes Mellitus
DI should not be confused with diabetes mellitus, which results from insulin deficiency or resistance leading to high blood glucose. Diabetes insipidus and diabetes mellitus are unrelated, although they can have similar signs and symptoms, like excessive thirst and excessive urination.
Diabetes mellitus (DM) is far more common than DI and receives more news coverage. DM has two forms, referred to as type 1 diabetes (formerly called juvenile diabetes, or insulin-dependent diabetes mellitus, or IDDM) and type 2 diabetes (formerly called adult-onset diabetes, or noninsulin-dependent diabetes mellitus, or NIDDM). DI is a different form of illness altogether.
Normal Fluid Regulation in the Body
Your body has a complex system for balancing the volume and composition of body fluids. Your kidneys remove extra body fluids from your bloodstream. This fluid waste is stored in the bladder as urine. If your fluid regulation system is working properly, your kidneys make less urine to conserve fluid when the body is losing water. Your kidneys also make less urine at night when the body's metabolic processes are slower.
In order to keep the volume and composition of body fluids balanced, the rate of fluid intake is governed by thirst, and the rate of excretion is governed by the production of antidiuretic hormone (ADH), also called vasopressin. This hormone is made in the hypothalamus, a small gland located in the base of the brain. ADH is stored in the nearby pituitary gland and released from it into the bloodstream when necessary. When ADH reaches the kidneys, it directs the kidneys to concentrate the urine by returning excess water to the bloodstream and therefore make less urine. |
