Writers have for descriptive purposes, and in most cases rightly, divided arterio-sclerosis into the two main types that I have described on p. 50--the hyperpiesis type and the atheromatous; but in general everyday practice we shall often come across cases that fall under neither head. Raised blood pressure, even to a considerable degree, 170 mm. to 180 mm., is frequently a temporary affair only, brought about by temporary causes, such as grief, anger, excitement or injudicious feeding. An altered mental outlook or a dose of calomel may banish it quickly; these cases are functional only. The wiser ones get to recognize their symptoms and the causes: these symptoms are chiefly a worried state of mind, irritability about little things, a sense of brain hurry, without the power to accomplish, and there may be passing vertigo and tinnitus. Such is the day of small things which should never be ignored, for the day of small errors unheeded may pass on into the long night of disease. CHAPTER III THE WAY OF SAFETY The pre-sclerotic state of raised pressure may last a considerable time--two or three years--but this can never be relied upon; every attack means extra work for the heart, and uses up for a time the reserve power of that long-suffering organ. Some hearts will respond well to the call for many years, but others give out and dilate. Continued raised pressure means one of two things--increased resistance and partial obstruction in the small arteries and capillaries, or increased ventricular action and force. An example of the first, which is far the more common, is seen in sclerosis; of the second, in aortic regurgitation. In the one case the heart is overcoming resistance--in the other, compensating for a leak. In the first, the error or departure from the normal is in the pipes--in the second, in the pump; but as both are vital organs and not mere bits of mechanism, they in time react on each other and both become altered. This change is, if vitality be strong, in the direction of conservatism, of accommodation to the new order of things. It is compromise, which may be effectual for a long time, but which, like most compromises, comes to failure in the end. Occasionally we find the sclerosis attacking the heart muscle itself or its arteries; such cases are obviously more serious. This condition generally comes on more or less at the end of the disease, but in a few cases quite early. Probably many of the cases of true angina pectoris occurring in early middle life are of this nature, the coronaries being the chief point of attack.