This is a video with Dr. Jill Carnahan about MCAS. She has overcome breast cancer, Crohn's disease and mold illness. She is a practicing Functional Medicine Doctor in Louisville, Colorado and is in fantastic health now! She talks about symptoms, triggers, testing and treatments- (over the counter drugs, prescription drugs and natural treatments). I don't have MCAS, but I do have histamine issues though and found this very informative and could relate to a lot of what she was saying. http://www.betterhealthguy.com/episode20 Key Takeaways What are mast cells and what do they do? What does a mast cell produce when over-activated? What are the symptoms of MCAS? What triggers overactivation of mast cells? What is the role of environmental toxins and MCAS? Is there a connection between MCAS and POTS? What role do food reactions and leaky gut play? What is the link between MCAS and CIRS? How is MCAS treated? Are some probiotics bad for people with MCAS? What mind-body tools may be helpful with MCAS?