The sciatic nerve is the longest, largest nerve in your body. Your sciatic nerve roots start in your lower back and run down the back of each leg. Sciatica is the pain or discomfort if your sciatic nerve gets compressed or pinched. People who are pregnant, have a sedentary lifestyle or have diabetes have a higher risk of sciatica.
Your sciatic nerve is a long, important nerve that starts just outside of your spine and then travels through your pelvis, into your butt and then to the back of each thigh in each leg. It's a mixed nerve, which means it has both motor (movement) and sensory (sensation) fibers. The sciatic nerve is the largest nerve in your body and is the major nerve to your leg. It allows you to walk, run and even stand.
People regularly state or are told they have sciatica. In fact, people sometimes use the term to describe symptoms that aren't included in the actual diagnosis. In addition, many feel that if they have sciatica, there are implications about the cause and the treatment. What is important to know about sciatica is:
Your sciatic nerve provides two types of functions:
Although your sciatic nerve passes through your gluteal muscles (butt), it doesn’t provide any nerve branches to these muscles.
The sciatic nerve starts just outside the base of your spine (lumbar spine and sacral region). It runs through the top of your gluteus muscles (butt) and down the back of your thighs (hamstrings) and lower legs (calves).
Where your sciatic nerve starts in your lower back is only about 1 centimeter (1/2 inch) wide. As the nerve extends down your legs, it widens slightly. At its thickest point, your sciatic nerve is about 2 centimeters (less than 1 inch) in diameter, or about the size of a penny.
Five different nerve roots make up your sciatic nerve:
These sciatic nerve roots join just outside the base of your spine to form the sciatic nerve. All the roots on the left side combine to form your left sciatic nerve while the same is true of the right side roots which combine to form the right sciatic nerve.
At your knees, your sciatic nerve splits into two main branches:
Your sciatic nerve also contains smaller branches at your:
Causes of sciatica can include:
Sciatic nerve pain may come and go or it may be chronic (long-lasting). Sciatica can also cause:
Often, sciatic nerve pain worsens if you stay in one position for long periods. It may also flare up when you move forcefully and suddenly, such as when you sneeze.
Your provider usually performs a physical exam to check the health of your sciatic nerve. Your provider may ask you to:
You may also have imaging tests to evaluate your sciatic nerve, including:
To reduce sciatic nerve pain and keep your sciatic nerve healthy, you can:
Some factors can increase your risk of sciatic nerve conditions, including:
A note from Cleveland Clinic
Your sciatic nerve is the largest nerve in your body, running down the back of each of your legs. Any condition that compresses or pinches your sciatic nerve may lead to sciatica. To prevent sciatica, stretch frequently, especially if you have a sedentary lifestyle. While sciatica is painful and can even be debilitating, it usually clears up with self-care
Last reviewed by a Cleveland Clinic medical professional on 06/15/2021.
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