Hypertension is a rapidly growing problem in developing countries. At the same time, due to its asymptomatic nature, the afflicted population is largely unaware of being hypertensive. Due to a lack of resources, routine medical exams are very rare in developing countries and many sick individuals remain undiagnosed. Using a large sample of hypertensive individuals from Indonesia, we show the importance of being diagnosed. Diagnosed individuals exhibit lower systolic and diastolic blood pressure, and overall lower probability of remaining hypertensive than undiagnosed individuals. We also show the main channels through which this is achieved: taking medication, routinely monitoring one's blood pressure, and engaging in moderate physical activities. We also point to channels through which additional benefits could be realized, but that are currently ineffective: dietary changes and maintaining a healthy body weight. Combined, these results point to the importance of directing public policy towards addressing the under-diagnosis problem and educating the public of the benefits of adopting a healthy lifestyle .