What causes numbness from the knee down to the foot?
Oct 12, 2022
Source: Cainiu Health
Dr. Yang Jun
Introduction
Numbness from the knee down to the foot can be caused by conditions such as common peroneal nerve injury, lower limb arterial embolism, and thromboangiitis obliterans. Common peroneal nerve injury is often due to trauma and manifests as reduced or absent sensation in the skin of the lateral lower leg and dorsum of the foot. Lower limb arterial embolism, commonly caused by atherosclerosis, leads to numbness from the knee down to the foot.
Numbness extending from below the knee to the foot is commonly caused by conditions such as common peroneal nerve injury, lower limb arterial embolism, or thromboangiitis obliterans. Patients are advised to seek treatment under medical guidance, including medications or surgical interventions.
1. Common peroneal nerve injury: This condition is often caused by trauma and primarily manifests as foot drop, inability to evert the ankle, reduced or absent sensation in the lateral lower leg and dorsum of the foot, and atrophy of the anterior and lateral muscles of the lower leg. It may lead to motor dysfunction; severe cases can affect muscles and joint tissues, potentially resulting in disability. The common peroneal nerve innervates the muscles responsible for sensation and movement in the lower leg and foot. When this nerve is damaged, abnormal sensations below the knee may occur. Treatment is primarily surgical, such as nerve decompression or nerve suturing, combined with the use of ankle-foot orthoses for supportive management.
2. Lower limb arterial embolism: This is usually caused by atherosclerosis, unhealthy lifestyle habits, obesity, or surgery. Local circulatory disturbances and blood stasis below the knee can lead to numbness extending from below the knee to the foot. Patients are advised to follow medical instructions for drug therapy, such as aspirin enteric-coated tablets or warfarin sodium tablets. Additionally, appropriate physical activity based on individual conditions may help alleviate symptoms.
3. Thromboangiitis obliterans: This condition is typically triggered by smoking, cold exposure, vascular trauma, or infection. Symptoms include cold intolerance, numbness, and pain, which may also present as numbness from below the knee down to the foot. Patients may be advised to take medications such as nicardipine hydrochloride tablets or aspirin enteric-coated tablets under medical supervision. In severe cases, treatments such as endovascular balloon angioplasty or lumbar sympathectomy may be considered under a physician's guidance.
