Headaches, anxiety, insomnia, brain fog, hives, and nasal congestion. These are just a few of the symptoms of mast cell activation or high histamine. Histamine symptoms are more common in women and often track with the menstrual cycle, occurring when estrogen is high at ovulation and then again just before the period.  The connection between … Continue reading The Curious Link Between Estrogen, Mast Cells, and Histamine