Diabetes insipidus is a condition wherein the kidneys are unable to inhibit water from being released, leading to an increase in urination and the feeling of extreme thirst. Unlike diabetes mellitus which has an increased blood glucose because of the lack of insulin, diabetes insipidus is a rare condition wherein the kidneys are not able to conserve water while filtering blood. This is probably due to vasopressin, an antidiuretic hormone. ADH is a hormone produced in the hypothalamic part of the brain and sent to the pituitary gland for storage and eventual release into the body. Central diabetes insipidus is caused by the lack of ADH while nephrogenic diabetes insipidus is because the kidneys cannot respond to ADH. Major symptoms include increased urination and excessive thirst. This excessive thirst allows patients to drink large amounts of water to replenish the water lost in the urine. This condition may have evolved from an inherited disorder wherein male children receive and cause the disease on the x chromosome from the mother to the female. Nephrogenic diabetes insipidus may be caused by the diseases of the kidney like polycystic kidney disease and the effects of various drugs. If the thirst mechanisms are working fine and fluids used are just enough, then there are no significant effect on the fluids of the body and salt balance. If there is a lack in fluids consumed, then dehydration and hypernatremia will set in the blood. Central diabetes insipidus is caused by a damage or tumor on the hypothalamus or pituitary gland.
Symptoms of diabetes insipidus include uncontrollable thirst, a yearning for ice water, increased urine volume of diluted urine reaching 2.5 liters a day in mild diabetes insipidus to 15 liters a day in severe conditions and if a lot of fluids were ingested. The average urine volume output for a healthy adult person is 1.5 to 2.5 liters a day. Another symptom of diabetes insipidus is nocturia, or the need to arise from bed in the evening just to urinate, and bed wetting. Children who have diabetes insipidus have the following signs and symptoms like crying that cannot be consoled, abnormally wet diapers, fever, nausea and diarrhea, and dry skin with the extremeties that are cold.
Usually, the kidneys are the ones responsible in clearing surplus body fluids from the blood. This excess fluid waste is kept in the bladder as urine. When the fluid regulation system of the body is functioning properly, the kidneys produce less urine to be able to conserve fluid when body water is decreased due to perspiration. To retain the volume and composition of the body fluids within normal levels the rate of fluid intake is governed by habits and thirst. The rate of excretion is greatly influenced by the production of ADH. This ADH is produced in the hypothalamus and normally stores the hormone in the pituitary gland. It is released into the body via the blood stream when necessary. ADH increases the concentration of urine by triggering kidney tubules to reabsorb water into the blood stream rather than directing it to the urine. Diabetes insipidus happens when this system is interrupted and the body cannot control its fluids. The way the body system is disrupted determines the form of diabetes insipidus that you have.
Central Diabetes insipidus is caused by the damage to the pituitary gland or hypothalamus due to surgery, a tumor or illness, inflammation or head injuy. Sometimes, the cause is not known. It is this damage that disrupts the normal production, storage and release of ADH.
Nephrogenic Diabetes insipidus is due to the destruction or damage of the kidney tubules. They are the ones responsible for the absorption and release of water. This defect makes our kidneys unresponsive to ADH. The defect may be due to a gene disorder or chronic kidney disorder. Some medications like lithium, tetracycline, can cause nephrogenic diabetes insipidus. One out of four cases of nephrogenic diabetes insipidus. Gestational diabetes insipidus occurs only during pregnancy and because of the destruction of ADH by the placental enzymes.
Genetically speaking, nephrogenic diabetes insipidus that appears in children after birth is usually due to a genetic cause that permanently damages the ability of the kidney to concentrate urine. It is common in the male population although the women can also pass the gene to the children.
To screen for diabetes insipidus, the doctor will perform several tests to determine the signs and symptoms of diabetes insipidus and diagnose it. A positive diagnosis of diabetes insipidus will make the doctor determine as to what type of diabetes insipidus it is by undergoing several tests such as the water deprivation test. In this test, you will be asked to cease drinking fluids about two to three hourse before the test to determine base values in the body weight, urine output and composition. They may also measure urine output and urine composition if fluids are not released. ADH levels in the blood are also used. In children this test is done under rigid medical supervision since they may lose more than five percent of their body weight during the test. A urine analysis is checking the physical and chemical examination of urine. A less concentrated urine means that the water is excreted is high. If the doctor feels that your form of diabetes insipidus is the inherited type, a complete family history will be taken from you as to polyuria and may probably recommend genetic screening.
Diabetes insipidus can affect your body in such a way that it retains an insufficient amount of water to be able to function properly thus leading to dehydration. Dehydration can cause dry mouth, a certain muscle weakness, low blood pressure or hypotension, a sunken appearance of the eyes, high fever and headache, a rapid heart rate or tachycardia, and weight loss.
Diabetes insipidus can also cause an imbalance in the amount of electrolytes circulating in the body. Electrolytes such as sodium, potassium, magnesium, calcium and phosphorus are responsible in maintaining body homeostasis. An imbalance may cause symptoms like headaches, weakness, pain in the muscle and touchiness.