It generally occurs because of lack of muscular strength, reason can be prolonged sitting /standing /travelling. You should consult a physiotherapist.
Next Steps
Go to a physiotherapist.. Ultrasonic therapy +IFT +Heating therapy +some strengthening as well as stretching exercises will be helpful for sure.
Health Tips
At home.. Rest +hot water fomentation +pain killer gel +no long sitting /standing /travelling /driving +no cold exposure +no manual exertions +no weight lifting +no forward bending +correct posture (sit tall).