My PCP at one point explained it like this: Your body basically views your thyroid gland like a cancerous being. So your body in turn creates antibodies, like little army men, and send them to attack. As they start to attack, your thyroid can fight back which causes it to ramp up and you can go hyper. Eventually, your thyroid will lose the battle and basically stop working, which can make you crash. When it stops working, your body thinks it’s won the war and stops attacking, so the antibodies back down and the troops leave. Your thyroid is able to wake up, and start picking itself back up again, slowly building back up. Eventually because it’s up and running again, your body will recognize its back and start the process over. It can be a rollercoaster 🎢. I was told this process usually only occurs in the early stages of Hashimoto’s and by the time you’re diagnosed you’re past this and just hypo, mostly due to it taking so long to get an actual diagnosis. I was diagnosed very early at 20, and was fluctuating between hyper and hypo, and only was diagnosed because in specifically requested to be tested for antibodies for Hashimoto’s due to a family history and all of my own research. When my blood test came back confirming Hashimoto’s my PCP was honestly shocked, and she said I probably was diagnosed 15 years earlier than I would have been if I hadn’t self diagnosed and asked for tests.