Where are your sciatica symptoms coming from?


What is sciatica back pain?

Sciatica is common in those who perform repetitive movements, have an awkward posture, or lift something heavy. Sciatica is a pain coming from the low back and radiating or shooting down the leg. However, this can become a blanket term for many different conditions which all need to be treated differently because they are coming from different sources.

Anatomy of the low back nerves

A quick anatomy lesson is needed in order to understand what can be causing sciatica, or sciatica-like pain in the legs. First of all, the lower back is made up of the lumbar spine, sacrum, pelvis, and the surrounding muscles. The lumbar spine and sacrum give rise to a number of nerves which form the lumbosacral plexus, which combines to form the sciatic nerve, a large nerve that travels down the leg.

Nerves that come out of the lumbar spine are numbered L1 to L5, meaning they come off of the spinal cord and make their way in the space between two vertebrae at different levels indicated by the number given. Same for the nerves coming out of the sacrum. The L4 to S1 nerves are the ones that are often affected and give rise to sciatica symptoms when they are irritated, pinched, or impinged.


Sciatic pain is triggered by pressure on nerves in the lower back or lumbar spine. Since the sciatic nerve comes from many nerves that start in the spinal cord in the lower back and goes all the way down to the toes, it is easy to see that many things can irritate it at many different levels. It is often difficult for a person to figure out by themselves where the pain might be coming from.

If the pain goes down the side or the front of your leg, it is not sciatica. These pain triggers could be coming from other nerves, joints, or muscles in the low back and hips, and if they persist, it is recommended you seek the advice of a medical professional.

True sciatica can come from a number of sources which range from disc herniation, arthritis, inflammation from a specific injury to the joints or surrounding tissues, and less commonly from other causes. Depending on the cause of your sciatica, the treatments can be very different. Knowing the triggers that cause you to feel pain can be very beneficial in providing a diagnosis.

The 5 most common causes of sciatica

Lumbar disc herniations

Lumbar disc herniation in this area is one major cause of sciatica pain. Discs sit between each lumbar vertebrae and act as a joint and cushioning between each vertebral level.

When discs are injured they often protrude or herniate (think of the jelly in a jelly doughnut being pushed out through a hole) which in turn can push on the spinal nerves, and cause severe pain. Symptoms of this type of injury include but not limited to

  • pain in the low back.
  • shooting or sharp or electric type pain down one or both legs into the foot, which can be accompanied by weakness or numbness.

If you experience any numbness in the groin/perineal region (not able to feel when you wipe after going to the bathroom), or difficulty controlling bowel movements or urination, this can be a sign of an emergency disk herniation, and you should go to your local emergency department.

Herniated disk
Low back disc herniation


Arthritis can be a cause of sciatica pain when the exit hole a nerve becomes smaller and applies pressure and irritates the nerve itself. Arthritis is a natural ageing process but it can also happen prematurely by trauma, falls, or accidents, as well as prolonged repetitive motions or activities. There is a disc in between each vertebra and this disc can degenerate and collapse on itself. This can cause a lot of pain as it may irritate the nerves coming out between two vertebrae. There are also joints that stabilise the vertebrae so they stay in line with each other and prevent the vertebra from slipping off the one below it. These joints which run along the back are called facet joints. They too can have arthritis and grow bone spurs that irritate the nerve that comes out of the spinal canal.

Disc degeneration
Facet joints degeneration

Inflammation from acute injuries

An acute injury is the result of an impact or a trauma of a specific area of the body. These acute injuries almost always lead to some inflammation. If inflammation happens close to these nerve roots of the spine, or close to the sciatic nerve, it can lead to sciatica pain. In this case, managing and treating the acute injury will ultimately result in sciatica going away.


Another area where the sciatic nerves can get pinched is by a muscle called the piriformis, in the deep gluteal/buttock area. The piriformis is responsible for internally rotating the legs (turning the toes inward) and when tightened or irritated, can push on the sciatic nerve. Symptoms of this type of injury can include pain in the gluteal area (usually on one side), accompanied by shooting/sharp/electric type pain down that same leg into the foot causing numbness or weakness.

Piriformis Syndrome

Referred pain

Referred pain is pain that comes from a different part of the body than the one where you feel the pain. Almost every organ, muscle, or joint in the body has a typical referral pattern. One of the best examples of this is the pain from a heart attack, which commonly refers to the left shoulder or the left arm. Or if you have liver irritation, you may feel it at the point of your right shoulder.

There are also two common areas which can refer pain which mimics sciatic nerve type pain but are not caused by the nerves of the lumbar plexus. These are referred pain from the sacroiliac joint and referred pain from trigger points or injury to the gluteus medius, a muscle in the buttocks.  

The typical referral pattern for the sacroiliac joint is into the buttocks area and down the back of the leg, usually stopping at the knee. This is similar, yet different than sciatic nerve type pain, which will often go below the knee into the foot or toes.  The gluteus medius when injured or aggravated has a common referral pattern down the side of the leg into the calf or side of the foot.

Get Assessed for your sciatica

These five common causes are not the only causes of what is known as sciatica. There are many other causes which affect different age groups and populations but are generally less common. It is impossible to rule out any of these conditions until you see a health care practitioner. If you are experiencing any leg pain in either one or both legs it is important to get yourself to your doctor, chiropractor, or physiotherapist to be assessed. Only once the origin of the pain is identified can it be treated directly, as there is no one size fits all approach to treating sciatica. 

Sciatica can become chronic if untreated. For more information on chronic pain, you can read these articles:

Treatment of sciatica

Once the cause of your sciatic pain is found, the treatment of sciatica and low back pain is then prescribed to provide relief and promote healing.

The treatment plan will consist of a combination of these techniques:

  • spine manipulation
  • spine adjustment
  • core strengthening exercises
  • stretches
  • acupuncture
  • Interferential Current/TENs machine
  • soft tissue therapy

While undergoing conservative treatments doctors may prescribe NSAIDS or other medications for pain relief and inflammation management. Should symptoms be severe enough or if conservative measures don’t bring enough relief, your physician may also refer you to a surgeon.