Pain in the lower back after sex, there are several reasons: 1, from the perspective of traditional Chinese medicine, consider that it is caused by kidney deficiency, men who have frequent sex will lead to loss of essence, pain in the lower back after sex, depression, etc. 2, men with pain in the lower back after sex, accompanied by radiating pain in the lower limbs, consider that it is caused by lumbar intervertebral disc herniation, kidney deficiency pain in the lower back only, will not radiate to the legs. 3, if it is female patients have pain after sex, most of them are considered to be caused by adnexitis and pelvic inflammatory disease. 4, female single sex time is too long or too intense, it will lead to sex organ damage, which will cause discomfort and even pain in the waist and abdomen after sex, which is also one of the common clinical causes.