Microneurography is a unique technique for directly recording muscle sympathetic nerve activity (MSNA) in man. The sympathetic nervous system (SNS) is fundamental to cardiovascular reflex control constantly regulating heart rate, blood pressure and peripheral vascular resistance. Many of the common cardiovascular diseases are associated with abnormalities of the SNS, including hypertension, heart failure, myocardial infarction, diabetes mellitus and insulin resistance. The microneurographic technique was set up in Leeds in 1996 (Drs Mary, Stoker & Greenwood) and was refined to include the recording of single-unit nerve activity to the peripheral vasculature. Using this technique, confirmation of the pathophysiological role of sympathetic hyperactivity in essential hypertension was established¹. Further work defined the relationship between left ventricular hypertrophy, blood pressure and MSNA in essential hypertension, as determined by echocardiography² and cardiac MRI³. One hypothesis as to the cause of essential hypertension has been neurovascular compression (NVC) of the rostral ventrolateral medulla. Using MRI to determine the presence of NVC in a group of subjects with a range of arterial pressures, greater sympathetic activity was found in those with NVC compared to those without, supporting the hypothesis that that NVC of the RVLM may cause sympathetic activation and hence be implicated in the pathogenesis of hypertension⁴. Both pregnancy-induced hypertension (PIH) and pre-eclampsia (PE) are poorly understood conditions, but remain a major cause of maternal death in the UK. Whilst many mechanisms have been proposed, abnormalities of the autonomic nervous system have been implicated. Using the microneurographic technique MSNA was found to be increased in normal pregnancy, PIH and PE, and to return to normal in the post-partum period^5,6. To summarise, the microneurographic technique for directly recording sympathetic nerve activity to the periphery has provided a unique insight into the mechanisms of human hypertension. Further studies will need to confirm whether therapeutic modulation of neurohormonal activation in hypertension will have a prognostic effect.