They can hurt, can’t they? Maybe these will help you:
https://www.mayoclinic.org/diseases-conditions/muscle-cramp/symptoms-causes/syc-20350820
https://my.clevelandclinic.org/health/diseases/muscle-spasms-muscle-cramps
Has this ever happened before? Were you sitting a while? How active are you? Just thinking… Maybe do some troubleshooting listed to rule things out. Hydrate, regularly stretch, etc. I can tell you I have muscle pain that has literally taken years to get better. But, if it is hindering you from daily activity or doesn’t go away with your troubleshooting a call to your doctor wouldn’t be a bad idea.