A group of autosomal recessive diseases known as congenital adrenal hyperplasia (CAH) are brought on by a deficiency in one of the enzymes necessary for the synthesis of steroid hormones in the adrenal cortex. Mutations in the genes encoding for these enzymes will result in an enzyme deficiency and, as a result, a block in the production of cortisol and/or aldosterone. Hypersecretion of ACTH, which results from negative feedback brought on by a lack of cortisol, causes the adrenal cortex hyperplasia, stimulates the production of intermediate products in steroidogenesis prior to enzyme blockade, and stimulates the production of steroids for which the missing enzyme is not required. Each enzyme deficiency presents as the associated clinical picture depending on which of the intermediate and end products of steroid production are found in increased or decreased amounts leading to either virilization of female children, deficient masculinization of male children, hypoglycemia, increased renal salt loss and hypotension, but on the other hand, hypernatremia and hypertension, with the fact that any of these symptoms can occur individually or in various combinations. The most common form of CAH is caused by a deficiency of the 21-hydroxylase enzyme. Lack of other steroidogenesis-related enzymes, coenzymes, or proteins can result in additional, more rare types of CAH. The clinical picture and measurements of steroid hormones and their precursors are used to make the diagnosis, which is then supported by molecular testing. These patients' lives can saved by an accurate and prompt diagnosis, which also establishes the course of treatment and follow-up and as well ensures adequate genetic counseling.