At the end of the childbearing period menstruation gradually ceases. In temperate climates this menopause occurs about the forty-fifth year, but it may come earlier or considerably later. Work that keeps a woman in a heated atmosphere, as cooking, washing, and baking, disturbs menstruation and tends to advance the menopause. Workers in chemical factories, in badly ventilated rooms, or women that do heavy labour in the open air, are apt to age prematurely, and have {243} an early menopause or "change of life." This premature climacteric is found also in women that bear many children in rapid succession. At the menopause there may be various physical or mental disturbances which are probably due more to the somewhat abrupt advent of old age, at the cessation of the childbearing part of life, rather than to the menopause itself. It is a fact, however, that often profound disturbances coincide with the climacteric, and we know no sufficient cause for them if the menopause itself may not be deemed such. There are numerous disorders of the nervous system in women which are dependent directly or indirectly upon a derangement of the pelvic organs. Distant parts of the body are affected pathologically through sympathetic irritation when the primary disease is in the pelvic organs, and direct treatment of the pelvic trouble alone cures these reflex conditions. The very common disorders of pregnancy, the marked physiological changes in women at the beginning of menstruation with puberty, and its cessation with the menopause, are among the first proofs of this assertion that occur. Menstruation may aggravate goitre, uterine fibroid tumours, skin diseases, and affections of the blood vessels. Disordered menstruation causes sleeplessness, melancholy, dementia, and mania, by affecting the brain; it may bring on local paralysis; start up latent epilepsy; excite reflex cough and difficulty in breathing; make the heart irritable; cause nausea, vomiting, dyspepsia, flatulence, diarrhoea, skin-inflammations, pain in the joints, and many other symptomatic phenomena. Chorea ("St. Vitus's Dance") is caused by various irritatations, and dysmenorrhoea can be such a cause. If a person is disposed to hysteria by neurotic inheritance, idleness, sedentary habits, vicious practices, excessive development of the emotions, any affection of the uterus or its appendages will greatly aggravate the outbreaks. The same is true in neurasthenia; and uterine disorders can directly cause neurasthenia, a condition described in another chapter. Migraine is an extremely severe form of headache which arises from various excitations, and uterine disturbances are among the causes. {244}