Back Pain and Sciatica

What is sciatica?

Sciatica is nerve pain from an injury or irritation to your sciatic nerve. In addition to pain, it can involve tingling or numbness in your back or butt that may also radiate down your leg. More severe symptoms are also possible.

Your sciatic nerve is the longest and thickest nerve in your body. It’s up to 2 centimeters wide (a U.S. penny or a United Kingdom 1 pence coin are about the same width). Despite its name, it’s not just one nerve. It’s a bundle of nerves from five nerve roots branching off your spinal cord.

You have two sciatic nerves, one on each side of your body. Each sciatic nerve runs through your hip and buttock on one side. They each go down the leg on their side of your body until they reach just below your knee. Once there, they split into other nerves that connect to parts farther down, including your lower leg, foot, and toes.

Having sciatica means you can experience mild to severe pain anywhere with nerves that connect to the sciatic nerve. The symptoms can affect your lower back, hips, buttocks, or legs. Some symptoms may extend as far down as your feet and toes, depending on the specific nerve(s) affected.

Types of sciatica

There are two types of sciatica. Regardless of what type you have, the effects are the same. The types are:

• True sciatica. This is any condition or injury that directly affects your sciatic nerve.
• Sciatica-like conditions. These conditions feel like sciatica but happen for other reasons related to the sciatic nerve or the nerves that bundle together to form it.

Healthcare providers tend to refer to both types as just “sciatica.” Their differences usually only matter when your healthcare provider determines how to treat them.

How common is sciatica?

Sciatica is a very common condition. About 40% of people in the U.S. experience some form of sciatica during their lifetime. It rarely happens before age 20 unless it’s injury-related.

Symptoms and Causes

What are the symptoms of sciatica?

Sciatica symptoms can include:

• Pain. Sciatica pain happens because of pressure on the affected nerve(s). Most people describe sciatica pain as burning or like an electric shock. This pain also often shoots or radiates down the leg on the affected side. Pain commonly happens with coughing, sneezing, bending, or lifting your legs upward when lying on your back.
• Tingling or “pins and needles” (paresthesia). This is similar to your feeling when a leg falls asleep because you sat cross-legged.
• Numbness. This is when you can’t feel sensations on the skin in the affected areas of your back or leg. It happens because signals from your back or leg are having trouble reaching your brain.
• Muscle weakness. This is a more severe symptom. Muscle command signals have trouble reaching their destinations in your back or legs.
• Urinary incontinence or fecal incontinence. This is a very severe symptom. It means signals that control your bladder and bowels aren’t reaching their destinations.

What causes sciatica?

Sciatica can happen because of any condition that affects the sciatic nerve. It can also occur because conditions affect any of the five spinal nerves that bundle to form the sciatic nerve.

Conditions that can cause sciatica include:

• Herniated disks.
• Degenerative disk disease.
• Spinal stenosis.
• Foraminal stenosis.
• Spondylolisthesis.
• Osteoarthritis.
• Injuries.
• Pregnancy.
• Tumors, cysts, or other growths.
• Conus medullas syndrome.
• Cauda equina syndrome.

What are the risk factors for sciatica?

Because sciatica can happen for so many reasons, there are many potential risk factors, which include, but aren’t limited to:

• Having a current or previous injury. An injury to your spine or lower back increases your risk of developing sciatica.
• Normal wear-and-tear. As you age, normal wear and tear on your spine can lead to pinched nerves, herniated disks, and other conditions that can cause sciatica. Age-related conditions like osteoarthritis can also play a role.
• Having excess weight or obesity. Your spine is like a construction crane when you stand upright. The weight you carry in the front of your body is what your spine (crane) has to hoist. Muscles in your back are like the winch and cable, pulling to keep you vertical. The more weight you have, the more your back muscles have to work. That can lead to back strains, pain, and other issues.
• Having insufficient core strength. Your “core” is the term for the muscles of your back and abdomen (stomach area). Like the crane analogy, having a stronger core is like upgrading the crane’s components to handle a heavier load. The abdomen muscles are important because they help anchor your back muscles.
• Your job. Jobs that require heavy lifting, a lot of bending, or working in awkward or unusual positions may increase your risk of lower back problems. However, jobs with prolonged sitting — especially without proper back support — may also increase your risk of lower back problems.
• Not using good posture and form when lifting. Even if you’re physically fit and active, you can still be prone to sciatica if you don’t follow proper body form during weight lifting, strength training, or similar activities.
• Having diabetes. Type 2 diabetes increases your risk of diabetes-related peripheral neuropathy. That damages your nerves, including any that can cause or contribute to sciatica.
• Physical inactivity. Sitting for long periods and lacking physical activity can increase the risk of sciatica.
• Using tobacco. Nicotine use can affect circulation and increase your risk of chronic pain. That includes conditions like sciatica.
• Unknown causes. Many cases of sciatica don’t have a cause that healthcare providers can find.

Understanding the potential complications of sciatica is crucial. While most people fully recover from sciatica, it’s essential to be aware of the possibility of chronic (long-term) pain as a complication. Most people recover fully from sciatica. However, a possible complication of sciatica is chronic (long-term) pain.

In severe cases, sciatica can lead to chronic muscle weakness, such as a condition known as “drop foot.” This occurs when nerve damage causes numbness in the foot, making normal walking difficult or even impossible.

Sciatica can also cause permanent nerve damage, resulting in a loss of feeling in the affected legs.