20s a bend on the pain may be and long-term sitting posture is not correct, lumbar disc herniation, acute lumbar sprain and urinary stones and other diseases. 1. Long-term sitting posture is not correct: young people in their 20s if long-term bent over work or half lying on the couch to read the phone and other bad habits, will cause the lumbar back muscles are in a state of tension for a long time, the formation of chronic lumbar muscle strain, in the bending of the waist there will be symptoms of pain. 2. Lumbar disc herniation: 20s if long-term heavy manual labor or weight lifting athletes, lumbar spine under pressure will cause lumbar disc herniation, stimulate the nerves will also appear lumbar pain symptoms. There will be the phenomenon of pain when bending over in your 20s. 3. Acute lumbar sprain: acute lumbar sprain when bending down will also be because of bending down and pulling the sprained lumbar muscles, resulting in the symptoms of lumbar pain. 4. urinary stones: young people in their 20s if they drink too little water or often drink instead of drinking water, may cause urinary stones, bending over to the ureteral stones have an impact on the ureteral spasm, stimulation of ureteral spasms, there will be bending over when the symptoms of pain. If the pain occurs when you bend over in your 20s, it is recommended that the patient go to the hospital for medical treatment to clarify the cause of the disease and receive regular treatment.