How to confirm sciatica? What examinations will a doctor perform, and which symptoms require immediate medical attention?

When pain radiates from the back to the feet, many people's first thought is sciatica, but to confirm whether it is sciatica requires examination, not guesswork. This article explains how the pain of sciatica travels, how to distinguish severe from mild symptoms, what tests a physician will perform, and which symptoms are red flags that require immediate medical attention. To understand the complete causes and treatment options for sciatica, you can refer to our site's featured article on sciatica. This piece focuses on "how to confirm."

How does the pain of sciatica travel?

It follows the pathway of the nerve. The sciatic nerve is composed of the fourth and fifth lumbar nerves and the first to third sacral nerves, running through the buttocks down into the lower limbs. When nerve roots are compressed (the most common cause being a herniated disc; other causes include foraminal stenosis due to lumbar degeneration, spondylolisthesis, and deep gluteal syndrome), pain or numbness radiates from the lower back along the buttocks, back and outer side of the thigh, down to the calf or even the sole of the foot. This characteristic of "radiating along the line" is the biggest difference between it and simple back pain.

How are mild and severe symptoms distinguished?

Mild: Intermittent tingling, numbness, or burning sensation in the lower back, buttocks, or lower limbs, which is more noticeable after sitting or standing for a long time, relieves after rest, and generally does not affect daily activities.

Moderate: Pain and numbness are persistent and prominent, radiating to the thighs, calves, or soles of the feet like a mild electric shock; inability to stand or sit for long periods, worsening when bending over, lifting heavy objects, or crossing legs, with physical activities beginning to be restricted. Actions that increase abdominal pressure, such as coughing or sneezing, will worsen the pain, which is also a common sign of nerve root irritation.

Severe: Severe pain, leg weakness or muscle atrophy, difficulty walking, or even problems with bladder or bowel control. At this stage, it is no longer within the scope of "wait and see."

Which symptoms are warning signs (red flags) requiring immediate medical attention?

Three warning signs. If any of these occur, please seek medical attention immediately—do not wait: fecal or urinary incontinence or difficulty urinating; numbness in the perineum (crotch, saddle area); or significant weakness in the lower limbs or rapid muscle atrophy.

These may indicate that the degree of nerve compression has affected vital functions and constitutes an emergency that must be addressed promptly.

If you do not have the above warning signs, but the radiating pain in your lower back and legs persists for more than a week without improvement, it is also recommended to seek medical evaluation early to confirm the location and cause of the compression, rather than relying on pain relievers long-term.

What examinations will the physician arrange first?

A physical examination is performed first, followed by imaging as needed. The most commonly used is the Straight Leg Raising Test (SLRT): with the patient lying flat, the doctor assists in raising the leg. If radiating pain in the leg is induced between 30 and 70 degrees, it indicates that the nerve root may be irritated. The doctor will also ask you to walk on your tip-toes and on your heels to test the muscle strength of your calves and feet, and check for sensory dullness or abnormal tendon reflexes.

The results of physical examinations can be affected by subjective descriptions and execution methods, so a physician's comprehensive judgment is needed before arranging imaging checks: X-rays are used to confirm spondylolisthesis, degenerative bone spurs, or disc space narrowing; MRI can clearly show the location and degree of nerve root compression; and CT is added if necessary.

If my leg hurts, is it definitely sciatica?

Not necessarily. In addition to nerves, the source of lower limb pain can also be blood vessels: vascular claudication caused by narrowing of the arteries of the lower limbs can also cause leg pain when walking, but its cause and management are entirely different. Differentiating between the two requires a doctor's confirmation through medical history, physical examination, and appropriate imaging or vascular studies. This is also why it is not recommended to self-diagnose the source of "back and leg pain."

Once confirmed, how is treatment arranged?

Depending on the cause and degree of compression, options range from medication and rehabilitation to interventional therapies. For a complete explanation of the causes and treatment methods, please see our site's featured article on sciatica. If your back and leg pain has persisted for some time and you want to confirm the cause, you can first perform a pre-assessment via LINE, and bring your past imaging data (X-rays, MRI) and treatment records to your appointment, so the physician can examine you and explain the appropriate next steps.

Written by: Dr. Ping-Sheng Lu
Peer Reviewed by: Dr. Ping-Sheng Lu July 2026

Disclaimer: This article is for health education purposes only and cannot replace a doctor's diagnosis and treatment advice. If any of the emergency warning signs described in the text occur, please seek medical attention immediately.