The Four Types Of Sciatica Explained

The importance of the sciatic nerve can't be understated since it's involved in our everyday actions, such as walking, standing, and running (via the Cleveland Clinic). For this reason, any problem with the nerve can impact even the smallest movement. One such issue is sciatica. It's uncomfortable pain due to intense pressure on the sciatic nerve. A 2022 review published in the journal StatPearls revealed that around 10% to 40% will develop sciatica in their lifetime.

According to Medical News Today, many people confuse sciatica with general back pain. However, sciatica isn't limited to the back. Sciatic pain usually spreads from the lower back, down to the buttocks and legs, explains Medical News Today. While the pain can range from mild aches to sharp burning sensations for some, the pain might feel like painful jolts or electric shocks for others (via the Mayo Clinic). 

Even though sciatica is common, there are different types, each coming with various causes and risk factors. Continue reading for more information on the different types of sciatica.

The four types of sciatica

There are four main types of sciatica, each being categorized by how long symptoms last and whether both legs are affected. They include acute sciatica, chronic sciatica, alternating sciatica, and bilateral sciatica. 

The factors contributing to acute sciatica vary and include smoking, height, age, and stress levels. According to a 2007 article published in the British Medical Journal, people with physically intensive occupations may be susceptible to the acute type of sciatica. Acute sciatica symptoms may last up to about six weeks and are characterized by lower back pain with pinching of the nerve as well as pain below the knee of one leg (via the American Family Physician).

According to Medical News Today, chronic sciatica is a long-term condition that causes continuous pain. Unlike acute sciatica, chronic sciatica lasts beyond three months and can disappear or reappear without proper treatment or lifestyle adjustments. 

While most sciatica cases involve one affected leg, the nerve pain associated with alternating sciatica can affect both legs simultaneously (via Spine Health). This type of sciatica is quite rare and often results in degenerative problems in the sacroiliac joint.

Bilateral sciatica is also rare and usually presents during exercise, as noted in a 2020 case study published in Cureus. The case involved a young athlete who experienced sciatic nerve entrapment to the popliteal fossa, the diamond-shaped space behind the knee joint. According to the study, this form of sciatica may lead to pseudo-claudication — characterized by pain, heaviness, and weakness when walking — due to compression of the spinal nerves in the lower spine (per Cleveland Clinic).

Causes of sciatica

Despite the different types of sciatica, the condition is generally caused by a herniated disk or overgrowth in the spine, which results in a pinched nerve, according to the Mayo Clinic. Various other causes exist. One example is lumbar spinal stenosis. This condition narrows the spinal canal causing a compression of the sciatic nerve, per Johns Hopkins Medicine. Pregnant women can also experience significant pressure on their sciatic nerves owing to the shifting of weights and loosening of ligaments induced by pregnancy during the second and third trimesters (via Harvard Medical School Health).

Other possible causes of sciatica include spondylolisthesis and piriformis syndrome. Spondylolisthesis happens when one spinal bone moves over the other, causing a kink in the spinal canal and pressurizing the nerves. As for piriformis syndrome, this uncommon neuromuscular disorder causes muscles in the buttocks to tighten and irritate the sciatic nerve (via the Cleveland Clinic). According to the source, some sciatica cases are also linked to a serious condition called "cauda equina syndrome," which affects nerves at the end of the spinal cord, causing leg pain and numbness around the anus, and loss of bladder control. 

Although many cases of sciatica are acute, some are can be long-lasting. According to Medical News Today, certain risk factors, listed in the next section, can make it more likely for people to develop this chronic condition.

Risk factors and symptoms of sciatica

According to Penn Medicine, men between 30 and 50 years are more likely to have sciatica. This implies that age and gender can be critical risk factors. A 2014 review published in the journal Physiotherapy Research International includes other factors such as social class, smoking, obesity, and occupation. According to the review, the chances of developing sciatica for the first time may reduce if some of these issues are addressed.

Apart from the aching pain in the lower back, people with sciatica may experience other symptoms, including muscle weakness and neuropathies, such as numbness or a tingling sensation, per the Hospital for Special Surgery. Sciatica symptoms may worsen depending on the location of the compressed nerve. Furthermore, some people may experience worse symptoms if they bend, lift objects, cough, sneeze or perform any action that involves the affected muscles or nerves, as noted by the hospital. 

Sadly, some sciatica cases come with serious or progressive neurologic deficits. If your symptoms are severe, it's important to let your doctor know. According to a 2014 study published in the European Spine Journal, sciatica cases where symptoms persist after six months may be referred to secondary care. In such situations, doctors recommend minimally invasive options like open microdiscectomy and endoscopic surgery to help treat sciatica, per the study.

How is sciatica diagnosed?

According to the University of Alberta, people can experience sciatica symptoms differently, and some cases occur without back pain. The vagueness of the symptoms emphasizes the need to seek a proper diagnosis from your doctor. Diagnosis often includes an assessment of your medical history, a physical examination, or a neurological test (such as the Lasègue's sign or the straight leg raising test), per a 2007 study published in the British Medical Journal.

Your doctor might also recommend other tests for further diagnosis. For instance, an X-ray of your spine might be needed to determine the presence of bone overgrowths pressurizing the nerve, per the Mayo Clinic. An MRI scan also provides detailed images of the herniated disks and pinched nerves. Likewise, an electromyography (EMG) test, which measures electrical impulses by the nerves, is another great alternative since a severe nerve root injury characterizes the condition, per the Mayo Clinic.

Lastly, a CT myelogram might also be needed. It involves injecting a special dye to help doctors identify abnormalities with the spinal cord and nerves, which may signal sciatica (via Healthline).

How is sciatica treated?

Many people with sciatica experience improved symptoms after six weeks of rest and medications (via WebMD). According to the source, acetaminophen and nonsteroidal anti-inflammatory drugs (like aspirin, ibuprofen, and naproxen) are usually the first considerations for treating sciatica symptoms. However, stronger muscle relaxants, anti-inflammatories, and tricyclic antidepressants are effective alternatives if over-the-counter drugs don't work, per WebMD. Chiropractic adjustments may help improve spine alignment, blood circulation, and muscle relaxation, according to Healthline. It may also help address other underlying conditions and worsening sciatica symptoms. Your doctor might also recommend various at-home stretching exercises or yoga to stretch your piriformis muscle and relieve pain. As most cases of acute sciatica come with relatively mild symptoms, you might start to see improvements after using a few of these self-care treatments, per Medical News Today

When sleeping at night, the National Health Service (NHS) recommends placing a small cushion or pillow between your knees at night when sleeping on your side. If you prefer to sleep on your back, placing several pillows underneath your knees is another option, per the NHS. According to the source, these best practices might help reduce the likelihood of sciatica returning after treatment. 

In severe sciatica cases, a 2014 report published in the journal Case Reports in Medicine describes lumbar laminectomy surgery as a promising treatment. Surgery might not be for everyone, so people should consider the benefits against the risks before making the final decision, says Johns Hopkins Medicine.