Sciatic Nerve Inflammation: Causes and Symptoms

Sciatic Nerve Inflammation: Causes and Symptoms
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Back pain in the lumbar region radiating into the lower limbs probably indicates a sciatic nerve problem. The medical terms used for these conditions are sciatic neuritis, sciatic neuralgia, lumbar radiculopathy, and radicular leg pain.


In most cases, we think of sciatica as pain in the lumbar region. The pain is uncomfortable, it moves, or radiates, to the sciatic muscle, and lower still towards the buttocks and legs.

Apart from pain, there are numerous other problems that present with sciatica, e.g. limited mobility in affected part of the spine, aggravated pain as a result of movement, muscle weakness, and increased skin sensitivity.

Difficulties can arise from damage to the intervertebral disc, insistence of the muscle, degenerative changes in the bones, but also from various other causes.

Medical terms used to describe for sciatic nerve inflammation and painful back:

Sciatic neuritis, sciatic neuralgia, lumbar radiculopathy, radicular leg pain.

In this article, we provide more information about the sciatic nerve and its inflammation. However, in this case it is not inflammation in its true sense.

Sciatic nerve - a brief overview

What is the sciatic nerve? 
Here is a briew look.

It is professionally referred to as the nervus ischiadicus.

It is a spinal nerve. It leaves from the roots of the spinal cord L4 - S3 (roots of the lumbar and sacral spinal cord). The root fibers (anterior and posterior) exit the spinal cord and together form the spinal nerves.

The sciatic nerve is the largest nerve in our body. Its thickness is comparable to the little finger of the hand. It is given an approximate diameter of about 1 centimeter.

After withdrawing from the spinal cord, it passes through the posterior region of the pelvis under the gluteus maximus muscle - musculus gluteus maximus. It then passes through the thigh and divides into two further branches at about the level of the knee: the n. tibialis and the n. fibularis communis.

It innervates, or supplies, a large part of the lower limb and the muscles of the lower limb, from the thigh and shin to the leg.

Its damage or oppression provokes unpleasant and intense pain and other neurological discomforts.

Sciatica is...

It refers to an unpleasant pain that radiates from the hip area. It usually shoots to one lower limb, and therefore more precisely to the back of the thigh, shin and in the most severe cases up to the leg.

The pain is accompanied by muscles weakness, up to impaired mobility and increased skin sensitivity in the area. Sciatic nerve problems impair mobility, cause pain when sitting and generally reduce quality of life.

The problems stem mainly from nerve compression, which can have a variety of causes.


The cause of sciatica is a compression of the sciatic nerve, which provokes irritation, which, in turn, causes intense and unpleasant pain. One of the medical terms is sciatica.

Difficulties can stem from various pathological conditions:

  • damage at the level of muscles and tendons.
  • injury
  • damage to the intervertebral disc.
  • degenerative changes of discs, vertebrae, osteochondrosis.
  • an anatomical anomaly, such as spondylolisthesis and other disorders of the position and curvature of the spine.
  • infection in a nearby area (tuberculosis of the spine is also an example).
    • acute infectious diseases with a complicated course.
  • lower back pain, swelling of the spine.
  • osteoporosis
  • ankylosing spondylitis - čalso called Bekhterev's disease
  • diseases of the pelvic organs
    • genitourinary system, kidneys
    • digestive system
  • a metabolic disorder such as diabetes.
  • autoimmune diseases
  • cancer

Pain in the area can also arise as a result of pregnancy.

The most common causes of sciatica are mechanical problems with the spine and its degenerative changes. These difficulties mostly stem from excessive overloading of the spine at a young age.

Examples include lifting heavy objects, improper handling technique or inappropriate bending and uncoordinated movements.

Table: the main causes of pain and discomfort stemming from spinal disorders

Functional impairments
Mechanical disorders that arise even without the presence of structural changes in the spine
  1. impaired static function - overload
  2. impairment of dynamic function - movement
That is, excessive overloading of the spine or inadequate movement is cited as the basis. Low back pain (lumbago) also falls into this category.
Degenerative changes
They arise most often as a result of wear and tear and aging of the body, as well as in response to overuse or injury. Often these are deformities of the vertebrae, articular surfaces or intervertebral disc disorders.
Spondylosis  as a reactive change at the edge of the vertebral body
  • formation of so-called osteophytes
  • also formed by damage to the intervertebral disc
  • osteochondrosis = degenerative changes of the disc (disc) + osteophytes
    • most often in the area of vertebrae C4 - C7 and L3 - S1
    • places with the greatest range of motion of the spine
  • more about the disease in the article on spondylosis
  • degenerative joint changes
  • occurs already in youth
  • the foundation is arthrosis
  • also arises from injury or damage to the disc or pathological curvature of the spine, the primary form has no clear cause
  • position shift between vertebral bodies
  • a common consequence is narrowing of the spinal canal
    • on the basis of which nerve oppression arises
Spinal canal stenosis
  • congenital (inborn)
    • has no significant clinical symptoms, but leads to future discopathy and other degenerative changes.
  • acquired
    • on the basis of disc bulging and the presence of osteophytes.
    • overlapping into the spinal (spinal) canal with subsequent oppression.
Dyscopathy  Intervertebral disc herniation The most common cause of mechanical compression
  • Bulging - total intervertebral disc enlargement
  • Protrusion - nucleus pulposus (soft elastic disc core) creates a hernia of the anulus fibrosus (a ring around the nucleus formed by fibres and cartilage), but does not move outside the disc
  • Extrusion - herniation - at nucleus pulposus penetration through anulus fibrosus, but without alteration of disc integrity
  • Sequester - in the separation of the nucleus pulposus from the discu

Risk factors leading to back problems

Some risk factors have also been cited in relation to the development of spinal problems.

1. Biological sex - is mainly directed towards a higher representation in the male population. The increased rate is mainly due to overloading of the spine in terms of occupation. When higher physical strength of men is applied in certain occupations.

2. Movement and position - this risk factor is present in jobs with long-term work in one position or with overloading on one side. In this case, gender is no longer decisive.

Similarly, a common cause is violent movement.

Poor posture or inappropriate sleeping position and poor sleeping mattress are also a problem.

3. Age - as a significant risk factor especially in the productive period of a person. And that is the increased onset of spinal problems from about 30 to 50 years of age.

4. Lifestyle - has an overall impact on health. In the case of spinal problems, sedentary work or a sedentary lifestyle and lack of exercise are particularly important.

The opposite of inactivity is the overloading of the spine under impact and unusual physical loads, especially in an untrained person.

5. Obesity and being overweight, together with a sedentary lifestyle, lead to long-term excessive strain on the spine. The result is back pain.

Interesting articles on overweight and obesity: 
What is the difference between overweight and obesity?
What is BMI and how it is calculated 
Overweight and obesity in young people and children

6. Vibrations with a frequency of 5 Hz result in damage to the core of the disc. Examples of vibration sources are heavy industrial jobs as well as professional truck drivers.

7. In degenerative process, smoking is also mentioned as a possible source of difficulty.

The 4 most common causes of sciatica

It is reported that among the most common causes of sciatic nerve pain is its oppression, which arises from 4 mechanisms.

1. Disc herniation

A bulging of the intervertebral disc, or disc herniation, causes oppression of the sciatic nerve. This mechanism ranks among the most common causes of various spinal pains. It may or may not occur, for example, after an accident and excessive strain on the spine.

2. Narrowed spinal canal

The vertebral canal (canalis vertebralis) has a tubular shape and is formed by the openings of the vertebrae. The spinal canal contains the spinal cord. 

The spinal cord runs through the spinal canal approximately up to the 1st and 2nd cervical vertebrae L1 and L2. Further on, a bundle of nerves branches off from it, which is also referred to as the cauda equina, or the horse's tail.

Narrowing of this canal, also referred to as spinal stenosis, is actually a narrowing of the space in the spinal canal. The narrowing is a source of oppression. It can occur after an injury or a degenerative process.

This cause is the less common of the 4 listed.

3. Spondylolisthesis

It is a displacement or slippage of the vertebral body relative to the lower adjacent vertebra. It most often occurs in the L and S region of the spine (L stands for the lumbar spine, S stands for the sacral spine).

The vertebrae are connected to each other by a complex structure of ligaments that stabilize them in a certain position relative to each other. The cause of displacement (olisthesis in Greek) can be damage to the bone, muscles or ligaments.

Spondylolisthesis is further categorised as follows:

  1. isthmic - violation of vertebral integrity in the area of the isthmus - vertebral arch
  2. dysplastic - developmental disorder of the articular surfaces of the vertebra
  3. degenerative - in degenerative change of the intervertebral disc and subsequently also of the joints
  4. iatrogenic - caused by spinal surgery

4. The "pear-shaped" muscle: musculus piriformis syndrome

Musculus piriformis, the pear-shaped muscle, is a small flat pelvic muscle in the gluteal region. It is located close to the sciatic nerve, below the largest gluteal muscle (musculus gluteus maximus). 

The muscle under certain conditions compresses the sciatic nerve, resulting in a variety of neurological disorders. Of course, also pain - ischalgia.

The cause is mainly contraction or increased tone, spasm of the pectoralis major muscle and compression of the sciatic nerve.

Often, pain occurs with prolonged sitting, and at a late stage after only 15 minutes. The problem is sitting on a hard mat or on a bicycle. The pain is aggravated by walking, walking up stairs or bending over with the lower limbs extended.

Common causes:

  • long-term sitting, sitting with the lower limbs crossed contributes even more
  • long-term driving
  • running, movement activities in a forward and backward direction, without rotational movements
  • sudden changes in direction of movement - football/soccer, basketball and other sports activities
  • biking/cycling, due to seating adjustment


Sciatica symptoms reduce quality of life, and not just because of the pain.

The pain may be of high intensity and aggravated by movement or prolonged inactivity. In pear-shaped muscle syndrome, it is even sitting that causes discomfort after only 15 minutes.

The pain is not in one place...

It can spread and radiate from the lower back to other areas:

  • sitting area - buttocks
  • back of the thigh
  • calf
  • towards the leg and the foot

The pain has the character of burning and pricking sensation, but it can also be throbbing.

It is aggravated by physical exertion and activity, but also by prolonged standing or sitting, such as bending over, coughing, and sneezing.

Sciatica is often manifested by pain at night.

It is associated with other neurological problems such as:

  • paresthesia - unpleasant sensation
    • sensation of tingling
    • feeling of numbness
    • sensation of itching
  • reduction of skin sensitivity - skin numbness
  • lower limb muscle weakness
  • reduced muscle tension along the nerve
  • impaired mobility, difficulty changing position, knee buckling
  • problems associated with passing stool or urine
  • impaired sexual function

Incidence of difficulties:
The onset of difficulties from 30 - 50 years of age.
70-85% will experience pain in the lumbar spine at least once in their lifetime. 

2-3% of people have radicular symptomatology.

When searching for information about sciatica, we may also come across the term lumboischiadic syndrome. The lumbofemoral syndrome is also described. The pain radiates from the lumbar or lumbar part of the back to the sciatic or thigh region.

Lumboischiadic syndrome is characterized by a triad of symptoms:

  1. Spinal dysfunction with spinal blockage (with restriction of movement) and pain present.
  2. Pain or paresthesias radiating into the thigh, shin or leg.
  3. Muscle weakness with decreased muscle tone and tension.

The difficulty may have the basis of a root syndrome or pseudoradicular syndrome.

Table: basic difference between radicular and pseudoradicular syndrome.

Radicular syndrome  Pseudoradicular syndrome
based on nerve compression no nerve compression
most commonly disc herniation and other structural changes  most often a disorder of the sacroiliac (SI) joint, lumbosacral joint, 
pain spreads over the dermatome
(area of innervation, i.e. nerve supply)
similar pain
but less segmentally circumscribed may be presen, 
does not spread below the knee
impaired sensitivity without concomitant neurological disorders  
muscle weakness - paresis
provoking manoeuvres aggravate the difficulty

Lumboischialgia (lumboischialgic syndrome)

Yo may have come across certain medical terms in the literature or on the Internet, if you were searching for the term sciatica or lower back pain.

Lumbo + ischi + algia.

It is sometimes abbreviated as LIS.

Lumbar area + sciatic nerve related + algia or pain = pain syndrome in the area of the shaft and sciatic region.

It is a term that refers to painful conditions in the lumbar, or cervical, spine. The pain is associated with limitation of mobility and radiating into the lower limb. 

Pain, tingling, and other sensations may radiate to the lower limb. The affected person may also be affected by other neurological complaints, e.g. muscle weakness, impaired sensitivity or impaired reflexes.


Diagnosis is determined by a doctor based on medical history, physical examination and neurological examination, e.g. body posture and positioning yourself are also evaluated in the diagnosis.

To pinpoint the exact cause of the difficulty, imaging methods are used, namely X-ray, CT and MRI, EMG (electromyography).

Differential diagnosis is important, the task of which is to reveal the exact cause of the difficulty, an example might be:

  • sciatica (lumbago) - a general term for lower back pain, without sciatic nerve irritation.
  • coxarthrosis - arthrosis of the hip joint
  • diseases of the abdominal cavity
    • ulcer disease
    • biliary colic
    • Diverticulitis
    • tumour
  • diseases of the retroperitoneum
    • kidneys
    • abdominal aortic aneurysm
  • gynaecological diseases
    • in women ectopic pregnancy
    • inflammation
    • tumour
  • shingles
    • neuralgia after herpetic inflammation
  • injury
  • diseases of blood vessels
  • cancer
  • inflammation in the spine
  • psychological causes


Difficulties may occur only once, return, or persist. Sciatica can be acute or chronic.

In the case of the chronic form, a medical examination and effective treatment are necessary to avoid unnecessary complications. Of course, the same applies to the acute form as well.

The exact course depends on the cause.

However, the lower the pain and other neurological problems radiate, the greater the likelihood of a more severe course of disease.

The pain begins in the lower lumbar and sacral regions.

It radiates from the gluteal area, runns down the back of the thigh, or sometimes up the calf. The pain can shoot through the entire lower limb towards the foot.

Paresthesias may also occur. Paresthesias are unpleasant tingling, itching and burning sensations. In someone they resemble chills. The paresthesias are accompanied by a decrease in skin sensitivity.

Muscles get weak. Mobility, change of position, long sitting or standing in one position, inactivity, become difficult.

The pain is mostly sudden and sharp. The affected person may lean to the side away from the pain, which relieves the pain, stand on the other limb, or feels stiffness at the affected site.

How it is treated: Sciatic Nerve Inflammation - sciatica

Treatment of sciatica: Medication, topical, regimen and rehabilitation

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