The remedy Allium Cepa gives us a really clear example of how homeopathy works.
You know how you feel when you chop an onion? Homeopathy is the medicine of like cure like, so these are the very symptoms that the remedy made from onion will ease. Allium Cepa is a primary remedy for hay fever with the streaming nose which burns and reddens that gap between your lips and your nose, and watery eyes. You may also feel dull-headed with these symptoms as well as feel stuffed up and sneezy. The remedies, and other hay fever remedies like it, address the symptoms without the drowsiness of some OTC medication.