 The acute porphyrias are acute intermittent porphyria (AIP), variegate porphyria (VP), aminolevulinic acid dehydratase deficiency porphyria (ALAD) and hereditary coproporphyria (HCP).These diseases primarily affect the nervous system, resulting in episodic crises known as acute attacks.The major symptom of an acute attack is abdominal pain, often accompanied by vomiting, hypertension (elevated blood pressure), and tachycardia (an abnormally rapid heart rate).