The hardness and tightness of the stomach in the 7th month of pregnancy may be caused by physiological factors, excessive exercise, preterm labor and other factors. 1. Physiological factors: 7 months pregnant has entered the late stage of pregnancy, the sensitivity of the uterus will increase at this stage, the pregnant woman may have false contractions, resulting in hardness and tightness of the stomach, which is a normal physiological manifestation. 2. Excessive exercise: If a pregnant woman in her 7th month of pregnancy still insists on exercises such as yoga, jogging, fast walking, etc., she may also experience the symptoms of hardness and tightness of the stomach. 3. Preterm labor: Preterm labor can be characterized by recurrent contractions, which can lead to hardening and tightening of the stomach. It is recommended that 7-month pregnant women avoid excessive exercise and relax. If the symptoms of hardness and tightness occur, you should consult a doctor in time to avoid delaying the condition and causing adverse consequences.