In recent days many women’s affected by breast cancer. Years between 1990 to 2014 rates of breast cancer dropped by 34 % in the US attributable to the combination of effective adjuvant therapies & improving in the earlier detection. In low & middle income countries breast cancer is increasingly problems. Historically it is observed that low incidence rates have been rising per year up to the 5%. Breast cancer cause due to various social causes also that is hormonal changes, Life style, weight. Stem cell have also important role in breast cancer. Because of these various reasons there is need to aware about breast cancer. In present study we tried to explain causes of breast cancer so we can easily understand that breast cancer is serious challenge that we have to carry and need to find out proper and cheap treatment on same.