Fundamentally, anger, greed and ignorance are at the root of all suffering. They are known collectively as the 'three poisons'. For example, anger is the cause of physical violence and war. Greed is behind the wastage of natural resources and pollution of the environment, ultimately leading to starvation and poverty. Ignorance, which means being blind to the consequences of our actions, causes disease. It is imperative, therefore, to deal with these 'poisons' if we are to free ourselves from suffering.
~ Pat Allwright, Basics of Buddhism