Medical abortion usually refers to medication abortion. The lumbar super soreness on the third day after a medication abortion may be caused by insufficient rest and nutrition of the organism, or it may be caused by incomplete medication abortion and uterine cavity infection. It is necessary to take proper bed rest and occasionally get out of bed after a medical abortion. Also need to supplement the body with certain nutrients, such as eating eggs, milk, etc., but should pay attention to a light diet; 2. Incomplete medical abortion: usually is not clean the uterine cavity of the villi and meconium tissue, there are uterine cavity residue, uterine cavity congestion, thus causing contractions resulting in the third day after the medical abortion lumbar super soreness, but also may have acute abdominal pain and other symptoms. Patients should immediately go to the hospital for examination and timely cleansing surgery treatment; 3. Uterine cavity infection: If patients do not pay attention to perineal hygiene and cleanliness after a medical abortion, it may lead to infection in the uterine cavity. Infiltration and exudation of inflammatory media in the pelvis may also cause lumbar super soreness on the third day after medical abortion. Medication, such as levofloxacin hydrochloride tablets, needs to be administered under medical supervision. If the pain is more severe, it can also be combined with ibuprofen extended-release capsules.