have had massive issues with this over the years. Tends to be terrys major and minor jamming up from a lack of balance in the body between strength of front, back and side bodies. Lots of yoga resolved it over time. but short term, anti inflammatorys, fixing pillow and bed. Towels under pillows is a quick fox if it’s too soft. Firm bed and firm pillows has been part of the solve for me. Rest up. Hope it comes good.