Category Archives: Endocrinology.

Tall stature

The commonest causes are hereditary (two tall parents!), idiopathic (constitutional) or early development. It can occasionally be due to thyrotoxicosis. Other causes include chromosomal abnormalities (e.g. Klinefelter’s syndrome, Marfan’s syndrome) or metabolic abnormalities. G H excess is a very rare cause and is usually clinically apparent. Acromegaly This is due to a pituitary tumour in almost

The Growth AXIS

Physiology and control of growth hormone GH is the pituitary factor responsible for stimulation of body growth in humans. Its secretion is stimulated by GHRH, released into the portal system from the hypothalamus; it is also under inhibitory control by GHRIH (somatostatin). GH stimulates the hepatic production of an intermediate (IGF-1, previously known as somatomedin C) that actually stimulates growth. Plas


The combined oestrogen-progestogen pill is widely used for contraception and has a low failure rate « 1 per 100 woman-years). ‘Pills’ contain 20-50 J.Lgof oestrogen, usually ethinyloestradiol, together with a variable amount of one of several progestogens. The mechanism of action is twofold: Suppression by oestrogen of gonadotrophins, thus preventing follicular development, ovulation and luteiniza


PATHOPHYSIOLOGY The extent of hair growth varies between individuals, families and races, being more extensive in the Mediterranean and Asian populations. Soft vellous hair on the face and elsewhere is not sex-hormone dependent, nor is hair on the forearm or lower leg. Hair in the beard, moustache, breast, chest, axilla, abdominal midline, pubic and thigh areas is sex-hormone dependent. Any excess in the lat

Disorders of sex and reproduction

CLINICAL FEATURES A detailed history and examination of all systems is required. Tests of gonadal function The patient and partner are their own best assay for gonadal endocrine function. A man having regular satisfactory intercourse or a woman with regular ovulatory periods is most unlikely to have significant endocrine disease, assuming the history is accurate (check with the partner!). When symptoms are pr

The menopause

The menopause, or cessation of periods, naturally occurs about the age of 45-55 years. During the late forties, FSH initially, and then LH concentrations begin to rise, probably as follicle supply diminishes. Oestrogen levels fall and the cycle becomes disrupted. Most women notice irregular scanty periods coming on over a variable period, though in some sudden amenorrhoea or menorrhagia occur. Eventually the

Reproduction and sex

Normal physiology of the female and male reproductive systems will first be considered, followed by their common disorders. Delayed puberty Over 95% of children show signs of pubertal development by age 14 years. In its absence, investigation should begin by age 15 years. Causes of hypogonadism (below) are clearly relevant but most cases represent constitutional delay: IN CONSTITUTIONAL DELAY, pubertal develo


This depends on the type and size of tumour and is discussed in more detail in the relevant sections (acromegaly, prolactinoma). In general therapy has three aims: 1 Removal/control of tumour (a) Surgery-usually via the trans-sphenoidal route is the treatment of choice. Large tumours are removed via the open transfrontal route. Radiotherapy is given if the tumour is incompletely removed. (b) Radiotherapy-exte

Presentations of Hypothalamic and Pituitary Disease

Pituitary space-occupying lesions and tumours Pituitary tumours are the commonest cause of pituitary disease and, as with most endocrine disease, problems may be caused by excess hormone secretion, by local effects of a tumour or inadequate production of hormone by the remaining normal pituitary, hypopituitarism. Nomenclature and biochemistry of hypothalamic, pituitary and peripheral hormones. Hypothalamic rel

Central Control of Endocrine Function

Anatomy Many peripheral hormone systems are controlled by the hypothalamus and pituitary. The hypothalamus is sited at the base of the brain around the third ventricle and above the pituitary stalk, which leads down to the pituitary itself, carrying the hyophyseal-pituitary portal blood supply. The important anatomical relationships of the hypothalamus and pituitary include the optic chiasm just above the pi