younger age. Developing world In tropical countries, the most common cause of heart failure is valvular heart disease or some type of cardiomyopathy. As underdeveloped countries have become more affluent, the incidences of diabetes, hypertension, and obesity have increased, which have in turn raised the incidence of heart failure. Sex Men have a higher incidence of heart failure, but the overall prevalence rate is similar in both sexes since women survive longer after the onset of heart failure. Women tend to be older when diagnosed with heart failure (after menopause), they are more likely than men to have diastolic dysfunction, and seem to experience a lower overall quality of life than men after diagnosis. Ethnicity Some sources state that people of Asian descent are at a higher risk of heart failure than other ethnic groups. Other sources however have found that rates of heart failure are similar to rates found in other ethnic groups. History For centuries, the disease entity which would include many cases of what today would be called heart failure was dropsy; the term denotes generalized edema, a major manifestation of a failing heart, though also caused by other diseases. Writings of ancient civilizations include evidence of their acquaintance with dropsy and heart failure: Egyptians were the first to use bloodletting to relieve fluid accumulation and shortage of breath, and provided what may have been the first documented observations on heart failure in the Ebers papurus (around 1500 BCE); Greeks described cases of dyspnea, fluid retention and fatigue compatible with heart failure; Romans used the flowering plant Drimia maritima (sea squill), which contains cardiac glycosides, for the treatment of dropsy; descriptions pertaining to heart failure are also known in the civilizations of ancient India and China. However, the manifestations of failing heart were understood in the context of these peoples' medical theories – including ancient Egyptian religion, Hippocratic theory of humours, or ancient Indian and Chinese medicine, and the current concept of heart failure had not developed yet. Although shortage of breath had been connected to heart disease by Avicenna round 1000 CE, decisive for modern understanding of the nature of the condition were the description of pulmonary circulation by Ibn al-Nafis in the 13th century, and of systemic circulation by William Harvey in 1628. The role of the heart in fluid retention began to be better appreciated, as dropsy of the chest (fluid accumulation in and