Swollen tonsils???? what's going on?

I went to the doctor today because my daughter has been eating really horribly. She has acid reflex, so I thought this could be the cause and her renitadine dose just needed changing. The doctor took a look at her throat and her tonsils are inflamed. It causes her to not want to eat, get stuffed up nose which causes her to get flem in her throat. Now that I think about it, she has had a stuffed up nose at least once a month, sometimes two times a month. Which means she has been having inflamed tonsils for a good couple of months now. What could be causing her to get inflamed tonsils. Could her acid reflux be causing it? people smoke in my house, but only a designated smoking room, never ever around her or anywhere the smoke could get out. I think that could contribute & make it slightly worse but I don't think it could cause the inflammation.