”Flashing back” is a kind of acute low back pain that often occurs in daily life, which is called posterior branch pain of lumbar spinal nerve in pain science, and also called “non-specific low back pain”, “small joint syndrome It is also known as “non-specific low back pain”, “small joint syndrome”, “lumbar strain” and so on. The pain can be recurrent and can be severe in the lumbosacral region and can overcharge to the thighs (but not the knees), which brings unspeakable pain to the patient and also makes the patient difficult to move and affects the patient’s daily life. What should I do if I have a “flash back”? In the acute phase of pain, patients should pay attention to bed rest, with anti-inflammatory and analgesic drugs, neurotrophic drugs treatment. Physical therapy can also effectively improve the stiffness of the back, such as laser or ultra-laser, especially for the elderly and frail patients, drug allergies. In cases of frequent recurrent attacks or if the pain lasts for a long time, nerve block treatment may be considered. A well-established posterior spinal nerve block treatment can provide both direct pain relief and relaxation of overly tense muscles in the lumbar region to improve their blood circulation, which is especially suitable for pain due to muscle tension and other causes with irreplaceable and rapid results. If the patient has a very clear pain point, local injection of anti-inflammatory and analgesic drugs can be considered, which is effective when applied directly to the lesion. If the patient has recurrent and severe pain, radiofrequency thermocoagulation treatment must be performed, using radiofrequency needles to directly destroy the lesioned nerve without affecting the surrounding tissues or organs, with positive results and no recurrence, which is also one of the best options.