The tightness and hardness of the stomach in the fifth month of pregnancy is a physiological contraction of the uterus. During pregnancy, the fetus grows and the uterus grows with it, which increases the sensitivity of the uterus, and when it is stimulated by the outside world, the uterus will contract and become tight and hard. This phenomenon can also occur if the fetus is moving around in the uterine cavity, which does not require special treatment. If you feel uncomfortable contractions, you can kneel on the bed, which can reduce the tension of the abdominal wall and reduce the uncomfortable symptoms, or you can use your hands to gently support the sagging abdomen, which can also reduce the uncomfortable phenomenon caused by contractions. You should try to pay attention to rest and not to overexert yourself. You also need to enhance nutrition and eat more fresh fruits and vegetables to help the growth of the fetus.