Mastocytosis and Mast Cell Activation Syndrome affect all systems, organs and tissues of the body. In particular, skin, liver, spleen, lymph nodes, bones and bone marrow, lungs, gastrointestinal system, eyes and blood are the most documented as adversely impacted by these diseases. Research exists but much more needs to be done to further identify and understand the less studied effects of mast cell disorders on the heart, brain and female reproductive system.