Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Indigestion ?
    ### Response:
    Indigestion can be caused by a condition in the digestive tract such as gastroesophageal reflux disease (GERD), peptic ulcer disease, cancer, or abnormality of the pancreas or bile ducts. If the condition improves or resolves, the symptoms of indigestion usually improve.
    