Sciatica is one of the common disorders known to cause moderate to severe pain along the course of the nerve. In most cases, the pain caused due to sciatica is persistent and long-lasting. It can interfere with the routine activities of the patient thus affecting the quality of life. If not managed properly, it may worsen causing serious complications like paralysis. Hence, it is important to be aware of what sciatica means, why it occurs, its warning signs, and the safe and effective treatments to manage it.
What is Sciatica?
Sciatica refers to the pain that usually begins in the lower back and radiates to the back of the legs along the course of the sciatic nerve. This nerve leaves the spinal cord from the space between the 2 lumbar vertebrae in the lower back and passes down through the hips and buttocks to the legs. Sciatica usually affects only one side of the body.  
Though the symptoms of sciatica are predominantly neurological in nature, the condition itself arises due to the abnormalities related to the bones called the vertebrae in the back. The most common underlying cause responsible for the development of sciatica is a herniated disc. It can also occur due to a bone spur of the spine or the narrowing of the spinal canal (spinal stenosis). The herniation of the disc occurs when the intervertebral disc present between the 2 adjacent vertebrae collapses or protrudes out. The backward protrusion of the intervertebral disc between the lumbar vertebrae, especially L4 and L5 vertebrae, results in the compression of the sciatic nerve due to which you may experience severe pain and irritation along its course. Similarly, a bone spur formed in the vertebral bodies of the lumbar region may press on the sciatic nerve causing irritation and pain. Spinal stenosis can contribute to the development of sciatica by reducing the space available for the nerve arising out of the spinal cord. 
Although the pain and irritation associated with sciatica are often severe, in most cases, the symptoms tend to resolve if the condition is diagnosed early and treated in an appropriate manner. However, if not managed properly, the compression of the sciatic nerve may become worse over time due to which the patient may develop significant weakness or paralysis in the leg usually with bowel and bladder changes. Being aware of the early signs of sciatica and seeking timely medical intervention is the key to avoiding these complications.
What are the signs and symptoms of sciatica?
The characteristic symptom of sciatica is the pain that arises in the lower back and radiates down the back of the leg. You may also feel mild to moderate discomfort at any site along the course of the sciatic nerve.  The intensity of the pain varies widely from mild to sharp and excruciating. In some cases, it feels like an electric shock or a jolt.
The pain often becomes worse while coughing or sneezing. This occurs as a result of the increase in the intraabdominal pressure while coughing and sneezing due to which the herniated disc or a bony spur may push or press on the sciatic nerve further.
As the compression of the nerve becomes worse, you may develop numbness and tingling along with the weakness of the muscles in the affected leg. This occurs due to the damage to the nerve causing it to lose its ability to transmit sensory and motor signals that carry impulses needed for creating sensations and muscle contractions, respectively.  Some other symptoms of sciatica include:
- Inability to control bowel and bladder movements
- Retention or incontinence of stools, and urine
- Difficult in walking and running
- Difficult in getting up from a sitting or a lying down position
- Stumbling while trying to get up
- David Davis; Kushagra Maini; Arvind Vasudevan, Sciatica, 2021
- Robert Goldsmith, BSc, MSc, MMACP, Nefyn Howard Williams, PhD, FRCGP, and Fiona Wood, MSc, PhD, Understanding sciatica: illness and treatment beliefs in a lumbar radicular pain population. A qualitative interview study, 2019 August, doi: 10.3399/bjgpopen19X101654, PMCID: PMC6970588, PMID: 31581116
- B Cortet, P Bourgeois, Causes and mechanisms of sciatic pains, 1992 March, 1;42(5):539-43
- David Davis, Kushagra Maini, Arvind Vasudevan, Sciatica, 2021 September, PMID: 29939685, ID: NBK507908
- Jean-Pierre Valat, Stéphane Genevay, Marc Marty, Sylvie Rozenberg, Bart Koes, Sciatica, 2010 April, PMID: 20227645, DOI: 10.1016/j.berh.2009.11.005