When stress is either extremely intense or has been going on too long, then the relaxed reserves in your nervous system tend to deplete. This gives your brain a wired feeling, meaning you are likely to be more anxious or irritable during the day and have poorer quality sleep at night. This has a major bearing on how your subconscious brain (hypothalamus gland) processes thyroid-related information, directly interfering with the normal production of TRH (thyroid releasing hormone), which in turn regulates your pituitary gland (TSH), and those overall regulation of your thyroid system. This will leave you with a mixture of hyper and hypo ...