This image shows symptoms of Mast Cell Activation Syndrome, from this article. I can personally attest to abdominal pain, cramping, bloating, nausea, vomiting, difficulty digesting certain foods, muscle and bone pain, muscle weakness, nerve pain, headache, neuropathy, difficulty concentrating, reduced attention span, brain fog, itching, rashes, hives, inflammation, swelling, flushing, inflammation of the eye or conjunctivitis, trouble focusing eyes, itchy and watery eyes, a burning sensation, ulcers on the tongue or in the mouth, coughing, wheezing, difficulty breathing, runny or stuffy nose, sneezing, sinus pain or pressure, enlarged spleen, elevated liver enzymes, high cholesterol, rapid heart rate, abnormal blood pressures (either too high or too low), fainting, anaphylaxis, chemical and environmental sensitivities (and more).