Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.

Labor contractions are the physical way your uterus tightens to promote delivery of your baby. All body muscles tighten and shorten (contract) when they’re being used. And the uterus is one of the ...

Medically reviewed by Andrea L. Braden, MD Key Takeaways Labor contractions can feel like intense cramps or pressure.Braxton-Hicks contractions do not follow a pattern and may stop with activity.Early ...