When bone metastasis occurs, numbness of feet is mainly considered that the tumor destroys the spinal cord or the compressed nerve root, mental abnormality and so on. 1. Damage to spinal cord: when the tumor occurs bone metastasis, if it damages the spinal cord, it will affect the sensory function, and the patient will have the symptom of numbness of feet. In serious cases, it may lead to paraplegia. 2. Compression of nerve root: if the tumor bone metastasis compresses the nerve root, it may manifest as sensory disorder of lower limbs, numbness of feet and other symptoms, accompanied by dull pain in the waist and other symptoms. 3. Mental abnormality: Bone metastasis with numbness of feet cannot be excluded to be accompanied with mental abnormality. After suffering from tumor, due to excessive psychological pressure, patients may have symptoms of numbness of feet due to mental abnormality. Under the guidance of doctors, patients with bone metastasis and numbness of feet should take reasonable treatment to prolong their life and improve their symptoms.