Causes
The condition is due to:
Bilateral idiopathic (micronodular) adrenal hyperplasia: 66% of cases
Adrenal adenoma (Conns disease): 33% of cases
Primary (unilateral) adrenal hyperplasia: 2% of cases
Aldosterone-producing adrenocortical carcinoma: <1% of cases
Familial Hyperaldosteronism (FH)
Glucocorticoid-remediable aldosteronism (FH type I): <1% of cases
FH type II (APA or IHA): <2% of cases
Ectopic aldosterone-producing adenoma or carcinoma: < 0.1% of cases

Genetics
40% of people with an adrenal aldosterone producing adenoma have somatic gain-of-function mutations in a single gene (KCNJ5). This gene is mutated in inherited cases of early onset primary aldosteronism and bilateral adrenal hyperplasia, albeit less frequently. These mutations tend to occur in young women with the adenoma in the cortisol secreting zona fasciculata. Adenomas without this mutation tend to occur in older men with resistant hypertension.Other genes commonly mutated in aldosterone producing adenomas are ATP1A1 ATP2B3, CACNA1D, and CTNNB1. Epidemiology
In the past, the prevalence of primary aldosteronism was considered to be less than 1% of patients with hypertension. More recent studies have reported much higher prevalence of primary aldosteronism, up-to 12.7% in primary care and to 29.8% in referral centers. Very low rates of compliance with screening guidelines lead to the underdiagnoses of primary aldosteronism. Pathophysiology
Aldosterone has effects on most or all cells of the body but, clinically, the most important actions are in the kidney, on cells of the late distal convoluted tubule and medullary collecting duct. In the principal cells aldosterone increases activity of basolateral membrane sodium-potassium ATPase and apical epithelial sodium channels, ENaC, as well as potassium channels, ROMK. These actions increase sodium reabsorption and potassium secretion.
Cervical effacement or cervical ripening refers to a thinning of the cervix. Background
Cervical effacement is a component of the Bishop score and can be expressed as a percentage.Prior to effacement, the cervix is like a long bottleneck, usually about four centimeters in length. Throughout pregnancy, the cervix is tightly closed and protected by a plug of mucus. When the cervix effaces, the mucus plug is loosened and passes out of the vagina. The mucus may be tinged with blood and the passage of the mucus plug is called bloody show (or simply "show"). As effacement takes place, the cervix then shortens, or effaces, pulling up into the uterus and becoming part of the lower uterine wall. Effacement may be measured in percentages, from zero percent (not effaced at all) to 100 percent, which indicates a paper-thin cervix. Results from a systematic review of the literature found no differences in cesarean delivery nor neonatal outcomes in women with low-risk pregnancies between inpatient or outpatient cervical ripening.Effacement is accompanied by cervical dilation. == References ==