Central Diabetes Insipidus: What it Is and What to Watch For

Central diabetes insipidus (central DI) happens when your body doesn’t make enough antidiuretic hormone (ADH), also called vasopressin. Without ADH the kidneys let go of too much water. The result is very dilute urine, strong thirst, and a risk of dehydration or high sodium levels. This isn’t the same as diabetes mellitus—blood sugar is usually normal.

Common signs and causes

Most people notice a few clear symptoms: peeing a lot (often several liters a day), waking up at night to urinate, and feeling constantly thirsty. Babies and small kids may be fussy, fail to gain weight, or wet the bed a lot.

Causes include head trauma, pituitary or hypothalamus tumors, pituitary surgery, infections, and autoimmune damage. Sometimes it’s genetic. If no cause is found, doctors call it idiopathic central DI.

How it’s diagnosed

Your doctor starts with history and simple tests: measure how much you drink and pee, check urine concentration and blood sodium. A key test is the water-deprivation test, where urine concentration is measured after controlled fluid restriction. If urine stays very dilute, a dose of desmopressin (a synthetic ADH) is given: if urine concentrates afterward, that points to central DI.

Imaging, usually an MRI of the brain, checks the pituitary area for tumors or damage. Blood tests rule out other causes. Diagnosis can be straightforward if symptoms are classic and tests match.

Treatment and practical tips

Desmopressin (DDAVP) is the main treatment. It replaces the missing hormone and cuts urine volume dramatically. It comes as a nasal spray, oral tablets, or injection—your doctor will pick the best form and dose. Once on treatment, you need follow-up to avoid hyponatremia (low blood sodium) from taking too much or drinking too much water.

Simple daily habits help: keep water available, note how much you drink and pee for a few days, and weigh yourself regularly—sudden weight changes can signal fluid problems. Wear a medical ID if you’re on desmopressin, especially if you travel or need emergency care.

If an underlying tumor or infection caused the DI, treating that condition may change your therapy. In rare cases, DI improves after the trigger is fixed.

When to call a doctor? Contact care quickly if you have severe weakness, confusion, extreme thirst, very low urine output after starting treatment, or symptoms in an infant like poor feeding or lethargy. Those can signal dangerously high or low sodium levels.

Follow your endocrinologist’s instructions, get regular blood tests, and adjust fluids and medication as advised. With the right diagnosis and care, most people with central DI can manage symptoms and stay well-hydrated while avoiding complications.