The clinical manifestations of hypopituitarism depend on which hormone is affected, how severe the deficiency is and the age at onset. The same missing hormone produces a different picture in a child than in an adult, and a deficiency that develops slowly is tolerated differently from one that appears suddenly.
The anterior pituitary hormones each have a distinct effect when they are lost. Growth hormone (GH) deficiency slows growth in children and changes body composition in adults. Gonadotropin deficiency, the loss of luteinizing hormone and follicle-stimulating hormone, causes menstrual disorders and infertility in women, and loss of secondary sexual traits and decreased sexual function in men.
Thyroid-stimulating hormone (TSH) deficiency and adrenocorticotropic hormone (ACTH) deficiency develop later in the course of pituitary failure than the other axes, because TSH and ACTH are more resilient to pituitary disease. TSH deficiency causes growth retardation in children. ACTH deficiency produces the secondary form of adrenal insufficiency, meaning cortisol deficiency that arises from the pituitary rather than the adrenal gland itself. It is characterised by hypocortisolism with a preserved level of mineralocorticoid production, so the hyperkalaemia of primary adrenal insufficiency does not appear. Prolactin deficiency causes a failure of lactation.
The posterior pituitary behaves differently. Antidiuretic hormone (ADH) deficiency is almost never a primary feature of pituitary adenoma-associated hypopituitarism; it occurs mostly with granulomatous and metastatic masses in the hypophysis, and it causes polyuria and polydipsia.
The table below lists the symptoms and signs of each hormone deficiency.
| Hormone | Presentation | Symptoms and signs |
|---|---|---|
| Adrenocorticotrophic hormone | Acute | Fatigue, weakness, dizziness, nausea, vomiting, circulatory failure. As in Addison’s disease, except lack of hyperpigmentation and absence of hyperkalaemia |
| Chronic | Tiredness, pallor, anorexia, nausea, weight loss, myalgia, hypoglycaemia | |
| Gonadotropins | Children | Delayed puberty |
| Men | Impaired fertility, impotence, reduced libido, decreased muscle mass and strength, decreased bone mass, decreased erythropoiesis and hair growth, fine wrinkles, testicular hypotrophy | |
| Women | Amenorrhoea, oligomenorrhoea, infertility, loss of libido, dyspareunia, fine wrinkles, breast atrophy, osteoporosis, premature atherosclerosis | |
| Thyroid-stimulating hormone | Children | Growth retardation |
| Adult | Fatigue, cold intolerance, constipation, weight gain, dry skin, slow relaxing reflexes | |
| Growth hormone | Children | Growth retardation, short stature, increased adiposity |
| Adult | Reduced exercise capacity, impaired psychological well-being, increased cardiovascular risk, increased central obesity, reduced lean body mass | |
| Prolactin | Decreased | Failure of lactation |
| Increased | Galactorrhoea, oligo/amenorrhoea, loss of libido | |
| Antidiuretic hormone | Polyuria, polydipsia including nocturnal |