Our nervous system transmits signals throughout the body. When nerves experience pressure or irritation, they send pain signals, leading to nerve pain. This discomfort often manifests as burning, tingling, numbness, or weakness in various body parts. Understanding nerve compression helps clarify how conditions impact physical sensations and movement.
Understanding Sciatica’s Typical Path
Sciatica is nerve pain originating from the sciatic nerve, the body’s longest and widest. It forms from five nerve roots (L4 to S3) in the lower back and upper sacral spinal nerves, extending through the buttocks and down the back of each leg. Symptoms include sharp, burning pain, tingling, numbness, or weakness radiating along this pathway, typically affecting one side. Pain may intensify with coughing or sneezing. This condition most frequently occurs when a herniated disc, bone spur, or spinal stenosis puts pressure on the lumbar spine nerve roots.
Why Sciatica Doesn’t Affect the Arms
True sciatica, by definition, does not cause arm symptoms. The sciatic nerve originates exclusively from nerve roots in the lower spine’s lumbar and sacral regions. This means sciatic nerve compression or irritation only produces symptoms in the lower body: the buttocks, thigh, leg, and foot. Nerves supplying the arms originate from a different spinal section: the cervical spine (neck) and upper thoracic spine. While nerve pain might feel similar in the arm or leg, their anatomical sources are separate, as the nervous system is segmented with different spinal regions controlling different limbs.
Nerve Compression in the Upper Body
Nerve pain in the arms typically stems from compression or irritation of nerve roots in the neck, known as cervical radiculopathy. This occurs when a cervical spine nerve is pinched as it exits the spinal cord. Symptoms include pain spreading from the neck into the shoulder, arm, hand, or fingers, often with numbness, tingling, or muscle weakness. Common causes are herniated discs or degenerative changes like bone spurs in the cervical vertebrae. Less common, thoracic outlet syndrome can also cause upper body nerve compression, resulting in arm and hand pain, numbness, or tingling, as it involves nerve or blood vessel compression between the collarbone and first rib.
When to Seek Professional Guidance
Consult a healthcare professional for persistent or worsening nerve pain, whether in your arms or legs. Immediate medical attention is warranted for sudden limb weakness, loss of sensation, or symptoms affecting both sides. Loss of bladder or bowel control alongside nerve pain also indicates a serious issue requiring urgent care. An accurate diagnosis is important for determining the most appropriate treatment plan.