There are four types of diabetes insipidus including:
This occurs if there is a low level of vasopressin or antidiuretic hormone (ADH) in the body. The deficiency means the kidneys are not prevented from excreting large amounts of urine and instead large volumes of dilute urine are expelled, even when the body has become dehydrated. This also causes blood to lose water and become more concentrated and higher in salt. This results in dehydration and stimulation of the thirst centre in the hypothalamus of the brain which causes a person to drink more.
This is the most common type of diabetes insipidus and it is mainly caused by disease, infection or injury to the pituitary gland or the hypothalamus gland.
The causes of cranial diabetes insipidus include:
The condition may be cause by an inherited mutation in the vasopressin gene, AVP-NPII which is transmitted to offspring in an autosomal fashion.
This condition describes when the ADH level in the body is normal but the kidneys do not respond adequately to the hormone. This may occur due to kidney damage or medications such as lithium reducing the expression of water channels in the kidneys called aquaporins.
Nephrogenic diabetes insipidus may be caused by:
Mutations in the genes that code for ADH receptors may be inherited and prevent these receptors from activating aquaporins in the kidneys. Inheritance is autosomal recessive in nature.