Neurally mediated hypotension (NMH) is a form of low blood pressure that originates from a miscommunication between the heart and the brain.

According to Dr Peter Rowe, a member of a research team in John Hopkins University, USA, neurally mediated hypotension can occur whether the structures of the brain and the heart are biologically proportionate or not. Neurally mediated hypotension can occur due to the lower volume of blood reaching the ventricles of the heart. Neurally mediated hypotension is known by various names, such as neurocardiogenic syncope, vasodepressor syncope, the vaso-vagal reflex, the fainting reflex and autonomic dysfunction.

The miscommunication that causes neurally mediated hypotension also causes an irregularity in the regulation of blood pressure during an upright posture. When a physically fit individual suffering from NMH stands up, gravitational forces cause approximately 10% − 15% of his/her blood to settle in the abdomen or limbs.

Medications and prevention methods can help control symptoms of NMH, but cannot completely cure it. Treatment of NMH is time-consuming and requires a lot of commitment and patience. Increased salt and fluid intake, physiotherapy, exercise and avoiding sitting down for extended durations can help to avoid extreme cases of suffering for NMH patients.