Low back and leg pain in the sixth month of pregnancy is usually due to two conditions: First, lumbar disc herniation, because after pregnancy with the increase in abdominal pressure, the amount of load borne by the lumbar region is enhanced, which may aggravate the degeneration of the lumbar disc, resulting in the aggravation of the lumbar disc herniation and the stimulation of the nerve roots to appear painful symptoms in the distribution areas related to the lower limbs, so there is pain in the lumbar region and legs. It is best to go to the hospital for an MRI of the lumbar spine to see if there is any obvious lumbar disc herniation formation and to have the doctor perform a body check test to see if the symptoms of lumbar disc herniation are positive. Second, the lumbar and legs due to the increase in body weight, increased load, resulting in muscle tissue showing excessive fatigue, strain, manifested as the symptoms of lumbar and leg pain, no obvious numbness and radiating pain, etc., you can apply warm water bags for waist and leg heat, you can also go to the hospital for infrared treatment, can effectively relieve the symptoms, but try to avoid drug treatment, in order to avoid the fetus However, try to avoid medication to avoid the impact on the fetus.