Sciatica is a symptom of a problem with the sciatic nerve, the largest nerve in the body. It controls muscles in the back of your knee and lower leg and provides feeling to the back of your thigh, part of your lower leg, and the sole of your foot. When you have sciatica, you have pain, weakness, numbness, or tingling. It can start in the lower back and extend down your leg to your calf, foot, or even your toes. It’s usually on only one side of your body.
Pain that radiates from your lower (lumbar) spine to your buttock and down the back of your leg is the hallmark of sciatica. You might feel the discomfort almost anywhere along the nerve pathway, but it’s especially likely to follow a path from your low back to your buttock and the back of your thigh and calf.
The pain can vary widely, from a mild ache to a sharp, burning sensation or excruciating pain. Sometimes it can feel like a jolt or electric shock. It can be worse when you cough or sneeze, and prolonged sitting can aggravate symptoms. Usually, only one side of your body is affected.
Some people also have numbness, tingling or muscle weakness in the affected leg or foot. You might have pain in one part of your leg and numbness in another part.
When to see a doctor
Mild sciatica usually goes away over time. Call your doctor if self-care measures fail to ease your symptoms or if your pain lasts longer than a week, is severe or becomes progressively worse. Get immediate medical care if:
Sciatica occurs when the sciatic nerve becomes pinched, usually by a herniated disk in your spine or by an overgrowth of bone (bone spur) on your vertebrae. More rarely, the nerve can be compressed by a tumor or damaged by a disease such as diabetes.
Risk factors for sciatica include:
Although most people recover fully from sciatica, often without treatment, sciatica can potentially cause permanent nerve damage. Seek immediate medical attention if you have:
It’s not always possible to prevent sciatica, and the condition may recur. The following can play a key role in protecting your back: