Scientific literature links them to vitamin B or D deficiency, long Covid, menopause/premenopause, anxiety, or cortisol abnormalities. You can start to decipher there; none of these are confirmed causes for me. Per a prior post, it can be a flight or fright response from the sympathetic nervous system. Again, I don’t feel validated personally without a more definitive diagnosis—which I’m starting to believe may or may not come.