Sciatica refers to pain radiating along the sciatic nerve, which branches from your lower back through your hips and buttocks and down each leg. It is a common condition, manifesting as mild discomfort or severe, sharp, or burning pain. This nerve pain can also include numbness, tingling, or muscle weakness in the leg or foot. Sciatica often involves periods of reduced symptoms followed by flare-ups, where pain intensifies.
Everyday Activities and Habits
Prolonged sitting, especially with poor posture, increases pressure on lumbar discs in the lower back. This pressure can compress sciatic nerve roots, leading to irritation and radiating pain down the leg. Sitting for over 30-45 minutes can also impede blood flow to the lower back and legs, reducing oxygen and nutrient supply to the nerves.
Improper lifting techniques frequently cause sciatica flare-ups. Bending from the waist or twisting your torso while lifting heavy objects places excessive strain on the lower back, potentially aggravating the sciatic nerve. Instead, bend your knees and squat, using leg muscles to lift, and avoid twisting your body when moving objects. Sudden twisting movements, even without lifting, can also provoke a flare-up.
Incorrect exercise form can contribute to sciatica. Activities like heavy squats, deadlifts, or high-impact aerobics place significant stress on the lower back and pelvic region, potentially compressing or irritating the sciatic nerve. Maintaining proper posture and form during physical activity prevents strain on the spine and surrounding muscles. Additionally, wearing certain shoes, such as high heels, can shift body weight forward, forcing hips to flex and potentially irritating the sciatic nerve.
Underlying Medical Conditions
Several medical conditions can cause sciatica flare-ups. A common cause is a herniated or bulging disc in the lower back. Intervertebral discs cushion spinal vertebrae; when their soft inner material pushes through the outer layer, it can press against and irritate a sciatic nerve root, causing radiating pain.
Spinal stenosis involves the narrowing of the spinal canal, which can compress the spinal cord and nerve roots. This narrowing often occurs due to degenerative changes like bone spurs or thickened ligaments, resulting in symptoms like numbness, tingling, or muscle weakness in the legs. Sciatica from spinal stenosis often worsens with standing or walking.
Piriformis syndrome occurs when the piriformis muscle, located deep in the buttocks, spasms or becomes tight, compressing the sciatic nerve. This compression can cause pain and numbness in the buttocks and down the leg, often exacerbated by sitting. Spondylolisthesis involves one vertebra slipping forward over another, putting pressure on spinal nerves and causing sciatica. Less common causes include tumors or infections, which can directly compress or irritate the sciatic nerve.
Broader Lifestyle and Environmental Factors
Beyond direct physical activities and specific medical conditions, broader lifestyle and environmental factors contribute to sciatica flare-ups. Chronic stress can lead to increased muscle tension throughout the body, including the lower back, exacerbating nerve irritation. Stress can also influence the body’s inflammatory response, worsening sciatica.
Obesity places additional pressure on the spine, increasing the load on intervertebral discs and compressing the sciatic nerve. Excess body weight can alter spinal alignment and posture, contributing to nerve irritation. Maintaining a healthy weight reduces this strain and helps prevent flare-ups.
Aging causes degenerative changes in the spine, like bone spurs and disc dehydration, which become common over time. These changes can narrow spaces where nerves exit the spine, making them more susceptible to compression. Poor diet, particularly one high in saturated fats, can contribute to weight gain and systemic inflammation, aggravating sciatica. Smoking also negatively impacts spinal health by reducing blood flow to spinal tissues and increasing inflammation, increasing sciatica risk.
How a Flare-Up Develops
A sciatica flare-up begins when the sciatic nerve becomes irritated, inflamed, or compressed. Sources include a herniated disc pressing on the nerve, or muscle spasms in the piriformis muscle. This pressure or irritation triggers a pain response.
Inflammation plays a significant role in intensifying pain during a flare-up. Degenerated discs, for instance, can release inflammatory proteins that directly irritate adjacent nerve roots. This inflammatory process contributes to the sharp, burning, or electric shock-like pain often associated with sciatica. The body’s pain response translates this nerve aggravation into radiating pain down the buttock and leg, sometimes extending to the foot.
Beyond pain, nerve compression can also manifest as numbness, tingling, or muscle weakness in the affected limb. These sensations occur as the nerve’s ability to transmit signals for sensation and movement is disrupted. The severity of these symptoms can vary, ranging from a mild ache to debilitating pain that impairs walking or standing.