I Have A Friend Who Is At The End Of

I have a friend who is at the end of her tether. Every month before and during her period she gets really ill, to the point where she has to call in sick to work. She often gets flu like symptoms but to the point where she is bed bound. This month she got it much worse. Swollen glands, white cactongue and very sore throat. The doctors say they don't know what's wrong. They've tak her off anti biotics after a week. I'm really worried because she is struggling to eat