The recent discovery of pathogenic mutations in genes encoding for succinate dehydrogenase subunits has led to the realization that pheochromocytomas and paragangliomas are much more often hereditary than was previously thought. Due to periodic surveillance of patients at enhanced genetic risk and a general increase in the frequency of abdominal imaging, an ever increasing proportion of the pheochromocytomas and paragangliomas is now detected preclinically, without the classic symptoms and signs. The diagnosis ofa pheochromocytoma or paraganglioma can be confirmed by measurement of the plasma levels and 24-hour urinary excretion of catecholamines, in combination with imaging. The therapeutic strategy will depend on the localisation of the pheochromocytoma or paraganglioma, its solitary or multiple presence, the absence or presence of excessive catecholamine production, and the gene involved.