A herniated lumbar disc can cause numbness in one of the limbs, which is a clinical symptom caused by the herniated disc pressing on the corresponding nerve root. In other words, a herniated disc is an imaging manifestation seen on CT or MRI images, and a limited protrusion of the disc is an imaging manifestation. The imaging may not necessarily cause clinical symptoms, but the protrusion may cause numbness in the lower extremities, especially in the lateral or posterior aspect of the lower leg, when it compresses the adjacent nerve root. Other movement disorders, such as dorsiflexion of the bunions or weakness of dorsiflexion of the ankle, are also symptoms. When a herniated lumbar disc causes the corresponding symptoms, it is not simply a herniated lumbar disc, but a herniated lumbar disc, which means that the imaging manifestations and clinical symptoms match, and only then is the clinical diagnosis of herniated lumbar disc made. Therefore, when combined with the clinical examination, the doctor will examine the patient to see if there are any changes in muscle strength or reflexes, and if so, the diagnosis will be clear. It does not mean that a herniated lumbar disc necessarily causes clinical symptoms, a herniated lumbar disc does not constitute a disease in itself, nor does it mean that numbness in the legs is necessarily related to the lumbar disc or the lumbar region, other causes may also manifest as numbness in the legs. But the combination of the two, if further proven clinically through physical examination, the diagnosis will be clear.