17a Hydroxyprogesterone is generally used to screen for congenital adrenocortical hyperplasia, a disorder caused by impaired synthesis of adrenal glucocorticoids. 17a-Hydroxyprogesterone is an endogenous hormone that synthesizes glucocorticoids and produces the precursors of glucocorticoids by the enzyme 21-hydroxylase, which in turn maintains the body’s endocrine function. Congenital adrenocortical hyperplasia is mostly due to the absence of 21-hydroxylase, so the patient’s body 17a hydroxyprogesterone level will be significantly elevated, may also appear depression, loss of appetite, vomiting and other clinical manifestations. If there is an abnormal 17a hydroxyprogesterone test result, it is recommended to consult a doctor in time to clarify the cause of the disease with the help of the doctor and carry out targeted treatment or therapy.