Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) congenital diaphragmatic hernia ?
    ### Response:
    Congenital diaphragmatic hernia is a defect in the diaphragm. The diaphragm, which is composed of muscle and other fibrous tissue, separates the organs in the abdomen from those in the chest. Abnormal development of the diaphragm before birth leads to defects ranging from a thinned area in the diaphragm to its complete absence.
    