History
Pubertas praecox is the Latin term used by physicians from the 1790s onward. Various hypotheses and inferences on pubertal (menstrual, procreative) timing are attested since ancient times, which, well into early modernity were explained on the basis of temperamental, humoral and Jungian "complexional" causes, or general or local "plethora" (blood excess). Endocrinological (hormonal) theories and discoveries are a twentieth-century development. See also
List of youngest birth mothers
List of youngest birth fathers
Premature menopause
Premature ovarian failure

References


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Left atrial enlargement (LAE) or left atrial dilation refers to enlargement of the left atrium (LA) of the heart, and is a form of cardiomegaly. Signs and symptoms
Left atrial enlargement can be mild, moderate or severe depending on the extent of the underlying condition. Although other factors may contribute, left atrium size has been found to be a predictor of mortality due to both cardiovascular issues as well as all-cause mortality. Research suggests that left atrium size as measured by an echo-cardiograph may be linked to cardiovascular disease. However, studies that have found LAE to be a predictor for mortality recognize the need for more standardized left atrium measurements than those found in an echo-cardiogram. Causes
In the general population, obesity appears to be the most important risk factor for LAE. LAE has been found to be correlated to body size, independent of obesity, meaning that LAE is more common in people with a naturally large body size. Also, a study found that LAE can occur as a consequence of atrial fibrillation (AF),  although another study found that AF by itself does not cause LAE. The latter study also showed that the persistent type of AF was associated with LAE, but the number of years that a subject had AF was not.Obstructive sleep apnea (OSA) may be a cause of LAE in some cases. When an OSA event occurs,  an attempt is made to breathe with an obstructed airway and the pressure inside the chest is suddenly lowered.