In outpatient clinics, we often see patients who visit the clinic for sciatica, many of whom have already learned about it on the Internet, so they are very purposeful when they visit the clinic. Some of them come to the clinic and directly ask for a lumbar MRI examination, but after the examination, they find no obvious abnormalities; others think it is just osteoarthritis of the hip joint and question the doctor’s recommendation to perform a lumbar MRI examination. Here is a brief introduction of sciatica related knowledge. 1.What is the sciatic nerve? The sciatic nerve is the thickest nerve in the body, starting from the spinal cord in the lumbosacral region, passing through the pelvis, and passing through the sciatic hollow to reach the buttocks, and then descending along the back of the thigh to the foot. Before reaching the N fossa, the sciatic nerve is divided into the tibial nerve and the common peroneal nerve, which innervates all the muscles of the lower leg and foot as well as the sensation of the lateral calf and foot. 2.What is sciatica? Sciatica is a syndrome with pain mainly in the area innervated by the sciatic nerve, and is a clinical symptom rather than a separate disease. Sciatica is divided into primary and secondary. Primary is rare, i.e. sciatica; secondary is common, which is a local and peripheral tissue lesion involving the sciatic nerve, commonly seen in lumbar disc herniation, lumbar spine osteophytes, inflammatory diseases of the sacroiliac joint and pear-shaped muscle contracture. 3.What are the clinical manifestations? 1) pain in the area of sciatic nerve innervation; 2) loss of sensation in the area of sciatic nerve innervation, which may be manifested as numbness; 3) decrease in muscle strength in the area of sciatic nerve innervation; 4) loss of Achilles tendon reflex or disappearance; 5) positive leg raising test. 4.What tests are needed? The main imaging examination is imaging, including lumbosacral spine, sacroiliac joint X-ray, lumbar spine CT and/or MRI, and if necessary, pelvic CT or MRI to exclude pelvic disease. If these tests are still not clear, neuro-electromyography is feasible to clarify the site of the lesion. 5. Is the pain here sciatica or not? Sciatica refers to the pain in the area of sciatic nerve innervation, while sacroiliac pain may be sacroiliac arthritis, fasciitis, sacroiliac joint tuberculosis, compulsory spondylitis, etc. This is not the same thing. So whether it is sciatica or not, it needs to be examined by a doctor to determine. 6.How to cure it? This is the most common concern of patients, but it is the most difficult question for doctors to answer, because the diagnosis must be clear first. As already mentioned above, sciatica is a clinical manifestation, not a separate disease, and nothing is known about it, so as a doctor, I don’t know how to treat it until there is a clear diagnosis! 7. Then, doctor, if you yourself have sciatica, what do you do? (You do not say, doctors are mostly tired of neck pain lumbago) Generally we will give appropriate treatment according to the patient’s age, lifestyle habits and clinical manifestations, before a clear diagnosis, which can also be called diagnostic treatment (to put it bluntly, try treatment without causing significant adverse effects, hehe). For young patients, there is no sensory impairment and muscle strength loss, in addition to sciatica, no other symptoms, you can advise patients to rest and exercise, physical therapy, give anti-inflammatory and analgesic drugs, if relieved, of course, all is well; no relief, or the emergence of new symptoms, then you can only go to the hospital to receive further examination! Isn’t it quite complicated? So, maybe you also looked up on the Internet, but still do not understand, that’s right, otherwise why do you have to study medicine for so many years and keep learning!