Buttock pain that radiates down the back of the thigh is commonly associated with sciatica, Mayo Clinic states. The pain may start at the lower back and continue along the calf, causing a burning ache, muscle weakness, numbness or a jolting shock. Sciatica typically develops when surrounding structures, such as bone spurs, pinch the sciatic nerve. Sciatic pain usually affects one side of the body and worsens during sneezing, coughing or prolonged sitting.
The sciatic nerve starts in the spinal canal and extends down the leg, according to Cleveland Clinic. Sciatica is often a symptom of a compressed nerve caused by an underlying problem. The most common cause is a slipped or herniated disc, but other related conditions include spinal stenosis, piriformis syndrome and spondylolisthesis. Spinal stenosis occurs when the spinal canal narrows and puts pressure on nerves, while piriformis syndrome develops when the piriformis muscle suffers abnormal spasms or tightness. Spondylolisthesis occurs when a vertebra slips out of place.
In rare cases, sciatica is a symptom of disease-related damage, such as diabetes, or pressure caused by a tumor, Mayo Clinic notes. Obesity and occupational strain are major risk factors for sciatic, especially when individuals perform sedentary jobs. Sciatic pain often resolves without treatment, but in lasting cases, doctors may recommend muscle relaxants, anti-inflammatory drugs, steroid injections, physical therapy or surgery.