### What is Cranial Diabetes Insipidus? Cranial diabetes insipidus, also known as central diabetes insipidus, is a rare condition that causes persistent thirst and frequent urination. This happens because of problems with the hypothalamus or pituitary gland in the brain. These parts of the brain are responsible for producing and releasing a hormone called vasopressin. Vasopressin helps the kidneys manage the amount of water in the body. ### How Does It Affect the Body? In people with cranial diabetes insipidus, the hypothalamus does not produce enough vasopressin, or the pituitary gland does not release enough of it. Without enough vasopressin, the kidneys do not retain water, leading to excessive urination. People with this condition can pass more than 3-3.5 liters of urine per day, and in some cases, more than 15 liters. This leads to constant thirst as the body tries to replace the lost fluids. ### Symptoms The main symptoms include: - Excessive thirst - Frequent urination Other symptoms can include dehydration, dry skin, and fatigue. ### Causes The most common causes are: - Head injury - Brain surgery - Tumors affecting the hypothalamus or pituitary gland In about a third of cases, the cause is unknown and is referred to as idiopathic diabetes insipidus. ### Diagnosis Doctors usually start with a physical exam and review of personal and family history. Other tests may include blood tests, urine tests, and imaging studies like MRI. ### Treatment The most common treatment is a synthetic version of vasopressin called desmopressin. It can be taken as a nasal spray, tablet, or injection. If the condition is mild, drinking more water may be sufficient. Treating the underlying cause, such as a tumor, may also be necessary. ### Outlook With proper treatment, the outlook for most people with cranial diabetes insipidus is excellent. Managing the underlying cause can lead to significant improvement in symptoms.