Consider diabetes insipidus if you experience excessive urination, around 4-8 liters per day; the urine is pale and free from sugar. Drinking less water may only cause discomfort without reducing urination.
The hormone ADH (antidiuretic hormone) functions to inhibit diuresis, produced in the hypothalamus, stored in the posterior pituitary gland, and then secreted into the bloodstream. When the concentration of ADH in the blood decreases, the ability to prevent diuresis diminishes or is lost, leading to frequent urination, increased thirst, and systemic disorders due to the large volume of urine being excreted. This condition is known as diabetes insipidus, which can occur at any age but is more commonly seen in teenagers, with a higher prevalence in males.
Diabetes insipidus can be primary due to a disorder in ADH production or secondary due to damage to the hypothalamus or pituitary gland. Secondary cases are often due to tumors, accounting for 30-50% of all cases. Any tumor in the hypothalamus or pituitary gland, or metastases from other locations, can lead to diabetes insipidus. It can also occur in individuals with malformations or abnormal development of the hypothalamus. In such cases, patients may present with symptoms of delayed neurological and sexual development, obesity, and retinitis pigmentosa.
Infections caused by chronic inflammation or sequelae of meningitis, encephalitis, head trauma, or surgeries near the pituitary gland and hypothalamus can also result in diabetes insipidus. Malformations or abnormal development of the hypothalamus are often seen in children, accompanied by other disorders such as intellectual and sexual developmental delays, obesity, retinitis pigmentosa, and syndactyly.
Primary diabetes insipidus is typically hereditary, often manifesting early, and may be familial or sporadic; it can also be sex-linked. Cases of diabetes insipidus with unclear etiology account for up to 30% of instances.
Pathophysiology: Normally, the renal tubules function to reabsorb water, concentrating the urine before excretion. When there is a deficiency of ADH, the reabsorption of water in the renal tubules is impaired, preventing the kidneys from concentrating urine. The body excretes a large volume of water, resulting in frequent urination that leads to dehydration in the body and cells, causing the patient to feel thirsty and requiring them to consume large amounts of water to compensate for the lost fluids.
Typical symptoms include: (which can appear gradually or suddenly following infection or trauma): Frequent urination of 4-8 liters per day, with severe cases reaching up to 40 liters per day; for young children, this may be 1-2 liters per day. The urine is pale, free of sugar and protein, and has a very low specific gravity. Drinking less water only leads to discomfort without reducing urination, and the specific gravity of the urine does not increase. Increased thirst: due to frequent urination, patients are often very thirsty and drink a lot.
Children often cry for water, and when given enough to drink, they stop crying. The amount of water intake closely matches the volume of urine output. Systemic symptoms: Initially, there may be little change, except in young children who may exhibit signs of chronic dehydration, gastrointestinal disturbances, vomiting, diarrhea, and constipation. The patient’s skin may appear dry and pale with reduced sweating; children may not gain weight, may show signs of malnutrition, and experience unexplained high fevers. If not provided with adequate water, patients may become dehydrated and experience cardiovascular collapse.
Upon noticing any suspicious signs as described above, individuals should seek medical attention immediately, especially at hospitals with endocrinology departments for testing, accurate diagnosis, determining the underlying cause, and appropriate treatment.
