1911 Encyclopædia Britannica/Albuminuria
ALBUMINURIA (Physiological or Functional), a term indicating the presence of albumin in the urine. This may depend on a number of morbid conditions, of which kidney troubles, acute illnesses and venous congestion are some of the commoner. But after exclusion of all known pathological causes, there still remains a large class of cases among subjects who appear to be in perfect health. This form has been called functional or physiological albuminuria, intermittent albuminuria, &c. Its recognition is of extreme importance, as it must be distinguished from the albuminuria due to Bright's disease and other troubles. The following are the main forms that have been described:—(1) Dietetic Albuminuria. This form affects some people after partaking of a meal consisting largely of albuminous foods, such as eggs. In others any extra indulgence in the pleasures of the table may give rise to it. (2) Cyclic Albuminuria. This name was first used by the physiologist Pavy, but other observers have called the same condition "postural albuminuria." It occurs in people enjoying perfect health, and is characterized by the presence of albumin in the urine at certain times of the day. It has been shown to depend entirely on the assumption of the erect position, and it disappears as a result of the recumbent position at night. (3) Albuminuria from exercise. This form affects some people after any unusual muscular exertion. (4) Prolonged mental strain or worry may give rise to a transient form of albuminuria. (5) Adolescent albuminuria is met with in some subjects, especially boys. The question of the real significance of "physiological" albuminuria is one about which there is much difference of opinion. But its importance and recognition—especially in questions of life insurance—admits of no question.