Weakness in the right leg may be caused by cervical spondylosis, lumbar disc herniation, stroke and other diseases. 1. Cervical spondylosis and lumbar intervertebral disc herniation: The low-level central nervous system generally refers to the spinal cord, which is located in the spinal canal, and its main role is to transmit various signals sent from the brain as well as to upload various signals to reach the brain, etc. When the spinal cord is compressed or damaged, weakness of the right leg may occur. When the spinal cord is pressurized or damaged, weakness of the right leg can occur, and common diseases such as cervical spondylosis, lumbar disc herniation, lumbar spondylolisthesis, etc.. 2. Stroke: Commonly known as stroke, stroke can be broadly divided into two categories: cerebral infarction and cerebral hemorrhage. The activities of the human body are mainly governed by the signals sent by the brain. When the motor area of the brain is damaged, it may cause abnormal signals or conduction disorders, and there will be movement disorders of the limbs, such as patients with hemiplegia after stroke. There may be other reasons for the weakness of the right leg, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.