When Should I Go to the ER for Back Pain?

Written by Michael Dreis, MD | Reviewed by Katie E. Golden, MDPublished on March 3, 2022

Key takeaways:

• Back pain can often feel severe and debilitating, but the cause usually isn’t a serious or permanent condition. The main causes of back pain are sprains, strains, and muscle spasms. 
• More serious causes of back pain include compression of the spinal cord nerves, broken bones in the spine, and infections in and around the spine.
• There are some things to look out for that could suggest something more serious could be going on — like weakness or numbness of the legs, changes in your ability to urinate or have a bowel movement, or a history of immunocompromise or cancer.

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Back pain is a common condition. It affects up to one in four people, and it’s one of the most common reasons people go to the emergency room (ER). While it can be significantly painful and disruptive to daily life, back pain usually isn’t a condition that threatens life or limb. It usually improves over time with gentle exercise, stretching, and over-the-counter medications. 

But there are some signs that back pain could be a sign of a more serious condition. Read on to find out more about what causes back pain and how to know when you should seek urgent medical care.

What causes back pain?

There are a lot of different reasons you may have back pain. By far, the most common causes of back pain are pulled muscles, sprains, and muscle spasms. These can happen from minor injuries to the muscles and ligaments in the back.

There are some other causes of back pain, but they aren’t as common. The causes correspond to conditions that affect:

• Vertebra: the bones that make up the spine
• Vertebral discs: the padding in between the bones of the spine
• Nerves: of the spinal cord
• Other organs: that aren’t related to the spine

Let’s go through these causes in more detail. Conditions that can affect the vertebra or the vertebral discs include: 

• Vertebral fractures: These are breaks and cracks in the bones that make up the spine. This can happen with things like motor vehicle collisions or even with minor falls.
• Degenerative changes: Bones, discs, and areas where they connect wear down over time. Conditions such as rheumatoid arthritis or osteoarthritis might lead to these changes.
• Herniated or ruptured discs: This can occur when the discs between the vertebrae change shape and position, similar to how jelly might squeeze out of a jelly-filled donut if you pushed down on it. There can be pain due to a lack of cushioning for the spine or a bulging disc that presses on nearby nerves.

Back pain can also come from a problem with the nerves in the spinal cord. Nerves leave the spinal cord at many different places along the spine. Some examples of problems with the nerves include: 

• Radiculopathy: This is a condition in which a nerve is compressed as it exits the spinal column. This could come from degenerative changes to the spine that narrow the nerve’s path or from a herniated disc that presses on it. It can cause back pain that shoots into one of the legs, often called “sciatica.” 
• Cauda equina syndrome: This is the compression of a special collection of nerves at the bottom of the spine. These nerves control things like bowel movements and urination. Different things can compress them, like herniated discs or even tumors.
• Spinal stenosis: This is when the tunnel that encases the spinal cord gets too narrow. It can happen if degenerative changes lead to misalignment of the vertebrae.

Infection can occur in different parts of the spine, like any other part of the body. But these types of infections are rare. They include: 

• Abscesses: pockets of infection that can form around the spine
• Discitis: infection of one of the intervertebral discs
• Osteomyelitis: infection of the bone

Finally, there are conditions that affect organs outside of the spine and can also cause back pain. These include conditions that affect the kidneys, such as kidney infections and kidney stones. An abdominal aortic aneurysm is another example. This is a condition in which the big blood vessel that travels through the abdomen becomes enlarged. In short, not all back pain involves the spine.

How do I know if back pain is serious?

While most back pain isn’t a sign of a serious medical condition, there are some situations where back pain might need urgent medical care.

The following symptoms might be a sign that something more serious than a muscle strain is going on:

• Fever can be a sign of an infection in the spine.
• Weakness or numbness of one or both of the legs can be a sign that a nerve in the back is compressed to the point that it can’t function properly. This can happen with many of the different conditions discussed above.
• Pain shooting down both legs, instead of just one, could be a sign of a more significant compression of the spinal cord. Radiculopathy and sciatica-like pain most often only occur down one leg.
• Difficulty with urinating or leaking of stool may suggest compression of the cauda equina nerves. This requires emergency treatment to prevent permanent damage to the nerves. You might not be able to urinate (urinary retention), control urination (urinary incontinence), or control bowel movements (bowel incontinence).
• Saddle anesthesia is numbness in the groin and perineum area (that would come into contact with a saddle if you were sitting on a horse). This can also be a sign of a problem with the cauda equina.
• Severe pain can indicate a more serious condition, particularly if the pain continues to worsen or you can’t get any relief with changing positions.

In addition to symptoms, there are also some conditions and circumstances that increase the risk that back pain could be due to a more serious underlying problem. They include:

• Severe trauma, like a car accident or fall off a ladder, can cause back pain that’s a sign of a broken bone or damage to other organs.
• Conditions that weaken the bones increase the risk for a fracture. This could be due to osteoporosis, which is age-related loss of bone strength. Medications can weaken bones as well, like long-term use of corticosteroids. 
• People who are immunosuppressed have a higher risk of serious infections of the spine.
• People who have used intravenous drugs have an increased risk of blood infections that can travel to the spine.
• People who have cancer may experience back pain, which could be a sign that cancer from somewhere else in the body has spread to the spine. Tumors in the spine can cause pain by themselves or lead to weakened bones that break easily.

It always helps to remember that you don’t need to have a life-threatening condition to seek care in the ER. Sometimes you might need to visit an ER for help with pain. This is especially true if the symptoms interfere with your ability to take care of yourself or carry out daily activities, like walking to the bathroom or standing in the kitchen to prepare food. ER providers are trained in both diagnosing and treating back pain — and no one should feel alone when dealing with severe pain.

The bottom line

Even though it can be extremely painful, most back pain isn’t a sign of a serious condition. It usually comes from muscle sprains and strains, and it will improve with time and treatment at home. But if you are experiencing severe back pain at home, the last thing you need is to also worry that something serious is going on. So it helps to know the symptoms that mean you should get an evaluation right away. But whether it is for diagnosis or treatment, never hesitate to head to your local ER for help.