Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Acute intermittent porphyria ?
    ### Response:
    How is acute intermittent porphyria (AIP) diagnosed? Diagnosis of AIP is suspected in individuals with otherwise unexplained severe, acute abdominal pain without physical signs. The finding of increased levels of delta-aminolevulinic acid (ALA) and porphobilinogen (PBG) in urine establishes that one of the acute porphyrias is present.
    