Die-off includes flu like symptoms. When the candida dies, it produces over a thousand different toxins that affect the body and nervous system. Other symptoms include headaches, ringing ears, achy joints, sore muscles, bloodshot eyes, dark urine, strong BO, tremors, heart palpitations, itchy skin, etc. The list can go on and on.
When you kill the yeast, you need to detox the toxins, otherwise you will feel bad. If you continue to kill the yeast without a detox plan, this can damage your liver from my experience, which will have to be healed at a later time (by a naturopath).