19 weeks + pregnant women recently always back pain may be physiological reasons, preeclampsia, lumbar spine disease and other causes. 1. Physiological reasons: with the increase of pregnancy weeks, the uterus is increasing in size, the lumbar spine load-bearing increase will cause a slight back pain, mostly in the appropriate rest, avoid standing for a long time and appropriate massage will gradually ease, is a physiological phenomenon. 2. Pre-eclampsia: there will be lower abdominal pain and lumbar pain and other symptoms, may also be accompanied by a small amount of vaginal bleeding, ultrasound suggests that the development of the fetus is normal, combined with the history and clinical manifestations can assist in the diagnosis. 3. Lumbar spine disease: for pregnant women with pre-pregnancy lumbar spine disease, with the increase of pregnancy weeks, the lumbar spine weight-bearing will also increase, may aggravate the condition and frequent lumbar pain, combined with the medical history, clinical manifestations and the necessary magnetic resonance imaging examination can assist in the diagnosis. 19 weeks + pregnant women who always have back pain recently need to go to the hospital in time to identify the cause and actively deal with it.