Acute and chronic low back pain is so common that 8 of 10 people experience it at some time in their lives. In fact, approximately 31 million people in the United States have low back pain at any one moment. And, one-half of all working Americans admit to having back pain symptoms each year.
With low back pain being so common, and with so much information available online, one would think that it would be easy to know the difference between acute and chronic low back pain.
But, after listening to many of my patients, I came to recognize and appreciate the fact that knowing and understanding the difference between acute and chronic low back pain is not that easy.
In this article, I will help you tease out the confusing noise and chatter you often find online by sharing with you 5 important differences between acute and chronic low back pain, and why you should treat each one differently.
What is the DURATION of acute vs. chronic low back pain?
The length of time low back pain exists or continues can be described as acute, subacute, or chronic. The duration of low back pain is generally considered to be the time between episodes, which might range from a few days to many weeks.
Different definitions have been recorded in the literature, but the commonly accepted definitions for the period of low back pain symptoms are:
- Acute – less than 1 month
- Subacute – between 2 and 3 months
- Chronic – more than 3 months since the onset of pain and symptoms
Sometimes people experience back pain that comes back or reoccurs again. One study reported that for people who experienced acute low back pain who were followed for 1 year, 65% reported one or more additional episodes of back pain.
As you can see, the variability in how long you’ve had your low back pain, whether it is acute, subacute, or chronic, will influence a lot of the decisions on how to treat your back pain.
This is when it can get confusing to a lot of patients.
In the United States, rarely is a patient treated by only one healthcare professional over the course of care.
From the time you initially experienced low back pain symptoms to the time it takes one healthcare professional to refer you to another, you may already have gone through the whole continuum of the back pain duration (from acute to subacute to chronic).
Imagine the different steps you’ll have to take in your journey to recovery:
- Initial episode of your low back pain.
- Call and schedule an appointment with your primary doctor.
- Meet with your primary doctor.
- Your primary doctor requests an X-ray or an MRI.
- You receive your X-ray or MRI result.
- Your primary MD refers you to an orthopedic doctor.
- Call and schedule an appointment with the orthopedic doctor.
- Meet with your orthopedic doctor.
- Your orthopedic doctor refers you to physical therapy for treatment.
- You FINALLY receive treatment for your low back pain!
And you’re supposed to treat your low back pain differently in each of the different stages…
No wonder why so many people are frustrated with the course of their back pain treatment!
What are the CAUSES of acute vs. chronic low back pain?
While there are many potential causes of acute low back pain, many of them actually have no serious underlying causes. In the vast majority of patients with low back pain, symptoms can be attributed to nonspecific mechanical factors.
Nonspecific mechanical factors are back pain that stems from the spine, intervertebral disks, or surrounding soft tissues. This includes muscle strain, disk herniation, lumbar spondylosis, spondylolisthesis, spondylolysis, and acute or repetitive traumatic injury.
These mechanical factors can result from:
- Injury from exercise, heavy lifting, or a sudden and awkward movement
- Muscle spasms
- Trauma from a fall or vehicle accident
- Osteoporosis or minor compression fractures
- Arthritis causing the hollow area around the spinal cord or nerves to narrow
- Bulging or herniated discs
Repetitive trauma and overuse injuries are also common causes of nonspecific mechanical low back pain.
In most cases, acute low back pain caused by nonspecific mechanical factors will not become chronic.
Acute low back pain develops suddenly, often as a consequence of an identifiable injury, and will either heal spontaneously or respond to the usual medical and physical therapy treatments you are familiar with.
In contrast, most chronic low back pain, though may initially be caused by structural or mechanical factors, does not develop from physical causes but is rather caused by neuroplastic pain.
Neuroplastic pain is caused by the brain misinterpreting messages from the body as if they are dangerous pain messages.
Normally, pain is helpful. Pain is a message.
Pain is our brain and body’s way of communicating with each other, telling each other, “Hey, there’s an actual or perceived threat to the body!”
With neuroplastic pain, you still feel pain even when there is no damage to the body or even after the initial injury has already healed.
In my book Back Pain Unlocked, I explained the role of your brain and nervous system (your body’s living alarm system) in interpreting these messages.
In “How To Effectively Treat Chronic Low Back Pain Using The Biopsychosocial Model”, I detailed a step-by-step framework on how to treat chronic low back pain using a brain training technique called graded motor imaging.
Now, some patients do have physical or structural reasons that caused chronic low back pain.
However, in a much smaller percentage of patients, some conditions may sometimes present with symptoms that could be mistaken for low back pain but could actually be something more serious and require a thorough medical examination.
Serious medical conditions that may mimic back pain include:
- Spinal compression or stress fractures
- Spinal infection
- Cauda equina syndrome
- Ankylosing spondylitis
- Abdominal aortic aneurysm
If you are experiencing unrelenting or constant back pain that interferes with your sleep, and/or accompanies an unanticipated weight loss, these could be symptoms commonly referred to as red flags. See your doctor and ask for a thorough medical evaluation.
As you can see, acute and chronic low back pain have very different causes and therefore should be treated differently.
What are the SYMPTOMS of acute vs. chronic low back pain?
Many of my patients describe their acute low back pain symptoms as one or a combination of the following symptoms:
- Sharp, stinging, or burning pain – This kind of pain can be accompanied by tenderness in the back, hips, and pelvis.
- Pain that travels down to the buttocks or leg – Sometimes low back pain includes a tingling, electric-like, or numb sensation that moves down the thighs and into the low legs and feet.
- Pain that feels better when changing positions – Some positions will feel more comfortable while other positions will aggravate your back pain. Depending on how your symptoms change with shifting positions, these can help identify the source or cause of pain.
- Pain that gets worst with prolonged positions or repetitive movements – Some of my patients report not being able to tolerate sitting for a long time or activities that require repetitive bending, like gardening or cleaning chores at home.
- Spasms in the lower back – Not only will you have pain and soreness on your back, but the muscles of your back will also tighten up and cause more pain.
Now, what confuses a lot of people is that these acute low back pain symptoms are the very same symptoms that one would find in chronic low back pain!
How can you tell if the symptoms are because of acute structural damages or chronic neuroplastic changes?
Here are some signs that point to neuroplastic pain as the most likely cause of your low back pain:
- Pain and symptoms triggered by stress – Does your low back pain get worst when you’re stuck in traffic? Or when you’re about to go to a sales presentation, a high-stakes meeting, or a job interview?
Stress puts your brain on high alert and can cause your nervous system to be hypersensitive to pain.
2. Persistent pain after the normal period of healing – On average, physical or structural soft tissue injuries resolve or spontaneously heal in 3 months or less.
If your low back pain is past the normal course or time frame for healing, your continuing low back pain is most likely caused by neuroplastic pain.
3. Your low back pain symptoms are inconsistent – Structurally caused pain generally does not have variability, and the pain and symptoms you have will be consistent regardless if you’re having a blast with your friends or having the worst kind of day.
4. A large number of symptoms – Assuming you don’t have a systemic disorder such as rheumatoid arthritis, lupus, or multiple sclerosis, having pain in three or four unrelated joints or body parts is highly unlikely.
A single underlying cause, most likely to be neuroplastic pain, is a reasonable explanation.
5. Delayed pain – This one can give you a lot of clues. If you experience low back pain an hour or more after completing an activity, the pain is most likely neuroplastic in nature.
With structurally caused pain, you would most likely experience the pain while still performing the activity.
Remember, structural pain heals fairly quickly. Most chronic low back pain is not structural, it’s neuroplastic in nature.
What is the TREATMENT for acute vs. chronic low back pain?
A variety of interventions are available to treat low back pain, but the latest clinical practice guidelines conclude that early intervention can help reduce the risk of conversion of patients with acute low back pain to patients with chronic symptoms.
If you do not want your back pain to spiral down to a chronic or recurring condition, timely treatment or intervention is critical.
Depending on your Back Pain Impairment/Function-Based Classification Criteria, the following treatments are available and recommended for acute to subacute low back pain:
- Manual Therapy Procedures – these are manipulation and mobilization techniques to improve your vertebrae’s segmental mobility or pelvic and hip mobility.
- Therapeutic Exercises – especially designed exercises to improve your spine and hip mobility, strengthen the muscles supporting your spine, and improve your endurance and ability to perform repetitive daily activities.
- Nerve Mobility Exercises – these are specific exercises that help improve the mobility of your central and peripheral nerves.
- Neuromuscular Re-education – promotes proper coordination of your muscles to provide stability to your spine while you are performing your daily functional activities.
- Manual or Mechanical Traction – produces positive results in nerve compression symptoms (although the use of lumbar traction therapy by itself is not recommended by the best available evidence.)
- Community/Work Integration – early return to work is associated with less disability.
- Patient Education – patient education in positions that promote symptom relief (centralization) and address fear-avoidance or pain catastrophizing behaviors.
- Progressive Endurance and Fitness Activities.
For chronic low back pain, addressing the physical, psychological, and social factors impacting your pain experience is the most sensible and effective way.
With neuroplastic pain causing most chronic low back pain, it is very important to use a comprehensive back program to address the different factors contributing to your experience of pain.
The latest evidence and studies on the neuroscience of pain have proven the efficacy of brain training, graded motor imagery, meditation, visualization, somatic tracking, and other cognitive-behavioral techniques in treating chronic pain conditions, including chronic low back pain.
What is the PROGNOSIS of acute vs. chronic low back pain?
To answer this question, we have to go back to the common causes of acute versus chronic low back pain.
As most acute low back pain results from nonspecific mechanical causes, depending on the extent of tissue injury, the expected healing period could be as short as a few days (i.e. muscle strain) or a few weeks to 3 months (i.e. herniated or ruptured discs).
For chronic low back pain, advances in pain neuroscience have now given us a myriad of tools to use without resorting to pain medications, steroid injections, and spinal surgeries.
Frequently Asked Questions
How many people experience lower back pain in their life?
Experts estimate that as much as 80% of the population will experience a back problem at some time in their lives. Most cases of back pain are mechanical or non-organic—meaning they are not caused by serious conditions.
What is the most common cause of lower back pain?
Low back pain is frequently the result of mechanical problems or soft-tissue injuries. These injuries or disorders may include disc damage, nerve root compression, and incorrect spinal joint movement.
A torn or pulled muscle and/or ligament is one of the most common causes of low back pain.
What percentage of low back pain is chronic?
About 20 percent of people affected by acute low back pain develop chronic low back pain with persistent symptoms at one year.
Even if pain persists, it does not always mean there is a medically serious underlying cause.
Knowing the differences between acute and chronic low back is critical in making informed decisions about your care.
Acute low back pain will usually heal or respond to the usual medical and physical therapy treatments you are familiar with. The cause of most chronic low back pain is most likely neuroplastic, instead of structural problems.
There are many evidence-based treatments available to you now without resorting to pain medications, steroid injections, and spinal surgeries.
Dr. Lex Gonzales, PT, DPT is an author and speaker who has been working as a licensed healthcare professional for over 24 years. On drlexgonzales.com he provides quality information and practical solutions you can use to achieve the best version of your healthy self.