In recent years, intensive selection has resulted in the development of metabolic diseases, including ascites, in chickens as a consequence of their genetic potential to grow rapidly. Many factors interact to cause ascites, including management practices, environmental conditions, and genetic makeup. In the modern broiler industry, ascites syndrome (AS), also called pulmonary hypertension syndrome (PHS), is regarded as the main reason for morbidity and mortality. Current meat chicken lines have a faster metabolic process, which requires a greater amount of oxygen, particularly when they are fed high nutrient density diets or when they are kept in cold environments, Due to their underdeveloped cardiorespiratory systems, broilers cannot get enough oxygen to meet their requirements and suffer from hypoxemia, which in turn leads to pulmonary hypertension syndrome. A wide range of management practices as controlled feeding protocols, and limited lighting periods, besides adding antioxidants to feed, are outlined for reducing ascites incidence in broiler chickens. Also, the use of higher levels of dietary vitamins such as C and E, besides selenium, is believed to help lower the incidence of ascites. The improvement of low-temperature environmental shelter conditions appears to reduce the prevalence of PHS. Molecular genetics employed to diagnose and select against susceptible broilers' grandparents is being employed to eliminate involved genes.