If a patient has sudden and severe back pain, it may be caused by acute lumbar sprain or lumbar intervertebral small joint syndrome, etc. Acute injury to the patient’s lumbar muscles, vertebrae, nerves and other tissues may result in sudden and severe back pain, or even inability to bend over. Patients are advised to seek medical attention for a clear diagnosis and appropriate treatment. Common causes of acute lumbago include: 1. Acute lumbar sprain: Mostly due to improper or excessive force on the patient’s lumbar muscles, fascia, ligaments and other soft tissues in the lumbar area are overstretched, thus causing acute lacerations of soft tissues, and the patient can experience acute severe lumbago. Patients are advised to brake immediately and seek medical attention with the help of family members. They can use ointments to relieve lumbar and leg pain, such as blood-strengthening ointment and pain-relieving ointment, as prescribed by the doctor; if the patient’s condition is serious, he can also use closure therapy to improve the symptoms. In addition, patients need to pay attention to bed rest to avoid physical labor to aggravate the injury; 2, lumbar intervertebral small joint syndrome: mostly due to improper lumbar posture or minor lumbar sprain to make the synovial membrane embedded in the joint, causing patients with severe pain and symptoms of limited activities, it is recommended that patients seek medical advice, under the guidance of doctors to improve the relevant symptoms through massage, acupuncture and other traditional Chinese medicine treatment. In addition to the above diseases, acute attacks of lumbar diseases such as lumbar disc herniation, lumbar muscle strain and lumbar fibrous tissue inflammation may also cause sudden onset of lumbar pain and even limitation of activities. Patients are advised to go to regular hospitals for relevant examinations in a timely manner to clarify the causes and treat them as early as possible.