Statistics show that approximately 40% of Americans suffer from sciatica at some point in their lifetime. Sciatica is a general term that refers to pain radiating down the leg caused by a pinched nerve, typically emanating from the spine. Most sciatica is caused by problems that affect the L4, L5, or S1 nerve roots along the spine, says Harvard Health.

“The pain travels along the sciatic nerve, which branches from your lower back through your hips and buttocks and down each leg,” explains Dr. Joslyn John, a physical medicine and rehabilitation specialist at the Kelsey-Seybold Clinic in Houston. “Usually, sciatica affects only one side of the body. This can cause inflammation, pain and often numbness in the leg.”

Damage to or pinching of the sciatic nerve, or the nerves that feed into it, can have several causes.

1. Herniated disc. Sciatica normally occurs when a herniated disc, also known as a slipped disc, presses on a nearby nerve. The disc really doesn’t slip, but the pain occurs when the jelly-like filling in the disc breaks through the outer shell and bulges through the tear. The material may press on a nerve causing abnormal signals to the brain. This becomes more common with age.
2. Spinal stenosis. Spinal stenosis in the narrowing of the spinal canal, which compresses nerves and can cause pain. Harvard Health says that the lumbar region of the spine has the most physical stress and is the area most affected by stenosis. Most often, it’s caused by a combination of age-related factors such as disc degeneration, osteoarthritis of joints, and thickened ligaments.
3. Spondylolisthesis. The bones of the spine are stacked on top of each other with discs in between. Spondylolisthesis occurs when one spinal bone slips forward in relation to the bone underneath it. For example, when L4 vertebra moves over the L5 vertebra, it can cause a kink on the spinal canal leading to pressure on a nerve root and sciatica.
4. Trauma. The sciatic nerve itself is susceptible to injury that affects the buttocks or stretches a hamstring. Falls, auto accidents, and sports injuries can lead to sciatica.
5. Pregnancy. Particularly during the third trimester of pregnancy, the shifting of weight from carrying the baby and loosening of ligaments can put indirect pressure on the sciatic nerve.

John says that the prevalence of sciatica is on the rise because of our sedentary lifestyles.

“It is common because we sit more than before, especially now with increased working from home. We are not walking to the car, walking to our offices, or even standing to get dressed anymore! We sit when we eat, when we work, and when we watch Netflix. Sitting is toxic to the discs of the spine. We need to sit less and build strength in our core muscles,” she says.

To prevent sciatica, move more. “Work on core strengthening exercises every day. Get up and walk around and take a break every hour from sitting at your desk,” says John. “Losing weight is helpful. Also be careful when lifting objects. Bend your knees and use your buttock muscles. When you are at the gym, never do dead lifts ─ they are not good for the back! “