Increased secretion of antidiuretic hormone (ADH)

Antidiuretic hormone (also known as vasopressin) is a 9-peptide hormone secreted by nerve cells in the supraoptic nucleus and paraventricular nucleus of the hypothalamus. It is released after reaching the neural pituitary via the hypothalamic-pituitary tract. Its main role is to improve the permeability of distally curved tubules and collection tubes to water, and to promote water absorption. It is a key regulating hormone for urine concentration and dilution. In addition, the hormone also enhances the permeability of the inner medullary collecting duct to urea. When severe vomiting or diarrhea causes the body to lose water, the osmotic pressure of plasma crystals increases, which can cause increased secretion of antidiuretic hormones.