In newborns and infants, the clinical picture of diabetes insipidus is significantly different from that in adults, and difficult enough to diagnose. These patients cannot express a desire for increased fluid intake, and if the pathology is not diagnosed in time, irreversible brain damage may develop. Newborns and those born prematurely with diabetes insipidus lose weight and develop hypernatremia due to perinatal hypothalamic injuries, urine osmolarity often reaches values less than 150-100 my / kg. The severity of the condition of these newborns is due to the underlying disease. Diabetes insipidus often disappears after weeks or months.
In older infants, the leading symptom in the clinic is repeated episodes of hypernatremia and vomiting. Lethal outcomes are associated with coma and convulsions. Other children grow poorly and gain weight, suffer from anorexia and vomiting while eating, are hypotensive, have constipation. A common cause of seeking medical attention is mental retardation. These symptoms are the result of a chronically reduced amount of hypertonic fluid in the body. Children may prefer water to milk. The urine osmolarity is never high, but its values may exceed the plasma osmolarity. Polyuria appears only in the case of increased consumption of liquids by the child. The disease often becomes symptomatic only after weaning the baby from the breast. By the time the diagnosis is made, the child usually has a pronounced lack of weight,dry and pale skin, no tears and perspiration.
If diabetes insipidus develops after a neonatal period, then the classic symptoms (polyuria and polydipsia) develop, as a rule, acutely. Patients prefer water to other fluids, the volume of liquid consumed reaches 10 liters per day or more. Polyuria can cause enuresis. Nocturia disrupts sleep, leads to fatigue. Explicit hypertensive dehydration occurs only in cases of impossibility to drink liquid. Appetite is often reduced, leading to weight loss.
Neurological symptoms in diabetes mellitus of hypothalamic genesis include headaches, vomiting, reduced visual fields. Hypopituitarism of hypothalamic origin is often associated with diabetes insipidus. Among patients with diabetes insipidus due to pituitary / hypothalamic tumors, 70% are GH deficient and 30% are deficient in other adenohypophysis hormones.