What diseases cause back and leg pain?

October 2, 2025 •

4 min read

Back and leg pain are common, but often misunderstood symptoms. A variety of underlying conditions can cause them, many involving nerve compression in the spine. Understanding what diseases cause back and leg pain is crucial for accurate diagnosis and effective treatment.

Quick Summary

Several diseases affecting the spine, such as herniated discs and spinal stenosis, can compress nerves and lead to pain radiating from the back to the legs, a symptom often called sciatica. Other causes include arthritis, piriformis syndrome, and certain infections or conditions like cauda equina syndrome.

Key Points

Spinal Origin: Many conditions that cause back and leg pain, including herniated discs and spinal stenosis, originate in the spine due to compressed nerves.
Sciatica as a Symptom: Sciatica refers to pain radiating down the sciatic nerve, but it is caused by an underlying condition like a herniated disc, piriformis syndrome, or spinal stenosis.
Herniated Discs: The most common cause, where a bulging disc presses on a nerve root, leading to sharp, shooting pain down one leg.
Spinal Stenosis: A narrowing of the spinal canal, often due to aging, which compresses nerves and causes leg pain that worsens with walking.
Medical Emergency: Loss of bladder or bowel control combined with back and leg pain can indicate Cauda Equina Syndrome, requiring immediate medical attention.
Non-Spinal Causes: Back and leg pain can also result from conditions unrelated to the spine, such as peripheral artery disease, endometriosis, or fibromyalgia.

Herniated Disc

Between each of your vertebrae are soft, jelly-like discs that act as cushions. A herniated disc occurs when the soft inner material pushes out through a tear in the tougher exterior, putting pressure on nearby nerves. This pressure can cause sharp, radiating pain that travels down the path of the affected nerve. If the herniation is in the lumbar spine (lower back), it can cause sciatica, a type of pain that shoots down the buttocks, thighs, and calves. Symptoms often affect only one side of the body and can worsen with certain movements like coughing or sneezing. In addition to pain, a herniated disc can cause tingling, numbness, or muscle weakness in the leg or foot. Most cases improve with time and conservative treatments, but persistent or severe symptoms require medical evaluation.

Spinal Stenosis

Spinal stenosis is a narrowing of the spaces within your spine, which can put pressure on the nerves that travel through it. This condition most commonly affects the lower back (lumbar spinal stenosis) and is often caused by age-related wear and tear, such as osteoarthritis. The narrowing can also be caused by bulging discs, thickened ligaments, or bone spurs. Symptoms often develop gradually and may worsen with walking or standing, but improve when sitting or leaning forward.

Symptoms of lumbar spinal stenosis can include:

Pain or cramping in one or both legs
Numbness or tingling in the legs or feet
Weakness in the legs
A heavy feeling in the legs

Sciatica (Nerve Pain)

Sciatica is a symptom, not a disease itself, but it’s a hallmark sign of many conditions that cause back and leg pain. It refers to pain that radiates along the path of the sciatic nerve, which branches from your lower back through your hips and buttocks and down each leg. Sciatica is often caused by a herniated disc, spinal stenosis, or other irritations that compress the nerve root. The pain can be a dull ache, a sharp, burning sensation, or a shooting electric shock.

Causes of Sciatica

Some of the most frequent causes include:

Herniated Disc: The most common culprit, where a disc puts pressure on the nerve root.
Spinal Stenosis: The narrowing of the spinal canal pinches the nerves.
Piriformis Syndrome: The piriformis muscle in the buttock region spasms and irritates the sciatic nerve, which runs close by or, in some cases, directly through it.
Spondylolisthesis: A vertebra slips forward over the one below it, irritating the sciatic nerve root.
Trauma: Injuries from accidents or sports can compress or damage the nerve.

Degenerative Disc Disease (DDD)

As you age, the discs between your vertebrae can lose height and hydration, losing their ability to cushion the spine. This degeneration can cause chronic low back pain that may radiate into the legs and buttocks, especially after certain movements or during periods of inactivity. The pain is often described as a dull, constant ache with intermittent periods of more intense, shooting pain. The body’s natural response to this process can also lead to bone spur formation, further narrowing the spinal canal and contributing to nerve compression.

Spinal Arthritis

Several forms of arthritis can affect the spine, causing pain and stiffness. Osteoarthritis is the most common and results from the wear and tear of cartilage in the spinal joints. Ankylosing spondylitis is a chronic inflammatory disease that primarily affects the spine and sacroiliac joints, leading to a hunched posture over time. When inflammation from arthritis puts pressure on the nerves, it can cause radiating pain, numbness, and tingling in the arms or legs.

Comparison of Common Spinal Conditions


Condition	Cause	Symptoms	Common Patient Profile
Herniated Disc	Disc ruptures or bulges, compressing nerve	Sharp, radiating pain down one leg (sciatica), numbness, weakness	Middle-aged adults, often due to heavy lifting or wear and tear
Spinal Stenosis	Narrowing of spinal canal due to age-related changes	Pain, cramping in legs that worsens with walking, improves with sitting	Older adults over 50
Piriformis Syndrome	Spasm or tightness of the piriformis muscle	Buttock pain radiating down the back of the leg, made worse by sitting	Athletes, individuals with sedentary lifestyles
Spinal Arthritis	Inflammation of spinal joints (osteoarthritis, ankylosing spondylitis)	Back stiffness, chronic pain, radiating pain, numbness	Older adults (osteoarthritis), younger men (ankylosing spondylitis)

Non-Spinal Causes

Back and leg pain aren't always caused by issues in the spine. Other conditions can cause similar symptoms, including:

Peripheral Artery Disease (PAD): This condition involves narrowed arteries that reduce blood flow to the limbs. It can cause cramping, pain, or aching in the leg muscles during exercise (a symptom called claudication).
Endometriosis: In some women, endometrial tissue growing outside the uterus can affect the sciatic nerve, causing cyclical pain in the lower back and legs.
Fibromyalgia: A chronic condition causing widespread pain, including in the back and legs, along with fatigue, sleep problems, and cognitive difficulties.
Kidney Stones: Pain can be felt in the back and radiate towards the abdomen, and sometimes into the groin or leg.

Cauda Equina Syndrome: A Medical Emergency

This is a rare but serious condition that requires immediate medical attention. It occurs when nerve roots at the end of the spinal cord are compressed, which can lead to permanent paralysis if left untreated.

Warning signs include:

Severe back pain
Weakness or numbness in both legs
Loss of bowel or bladder control
Saddle anesthesia, or loss of sensation in the inner thighs, buttocks, and perineal area

Conclusion

Identifying the precise cause of simultaneous back and leg pain can be complex, given the wide range of potential conditions. From common issues like herniated discs and arthritis to rarer conditions like cauda equina syndrome, a thorough evaluation by a healthcare professional is essential for proper diagnosis and effective treatment. Ignoring persistent or worsening pain can lead to serious complications. For more in-depth information on back pain, consult reputable sources like the Cleveland Clinic: Back Pain Causes, Treatment & Pain Relief.

Frequently Asked Questions

Yes, while often caused by less severe issues like muscle strain, back and leg pain can signal serious conditions such as a severe herniated disc, spinal stenosis, or, in rare cases, cauda equina syndrome. It's important to see a doctor for a proper diagnosis.

Both can cause radiating pain down the leg, but sciatica is a symptom caused by nerve compression anywhere along its path, typically in the spine. Piriformis syndrome is a specific cause of sciatica where the piriformis muscle in the buttocks spasms and irritates the sciatic nerve.

Yes. When arthritis affects the facet joints in the spine, it can lead to inflammation and bone spur formation. This can narrow the nerve pathways and compress nerves, causing pain, numbness, or tingling that radiates into the legs.

Pain from a herniated disc often feels sharp or burning, and it usually affects only one leg. It might worsen when coughing, sneezing, or sitting. A doctor can confirm the diagnosis with a physical exam and imaging tests like an MRI.

No. Many conditions, including herniated discs and piriformis syndrome, can be effectively managed with conservative treatments such as physical therapy, medication, and rest. Surgery is typically reserved for severe, persistent cases.

Yes, prolonged sitting can contribute to pain by weakening core muscles and causing issues like piriformis syndrome. Maintaining poor posture while sitting puts added pressure on the lower back and hips, irritating nerves.

For new or mild pain, initial steps include rest, applying ice or heat, and taking over-the-counter anti-inflammatory medication. However, if the pain is severe, persistent, or accompanied by weakness or bowel/bladder issues, it is essential to see a doctor.