¿Cuáles son las causas del dolor crónico?

Chronic pain has a nasty habit of showing up uninvited and then refusing to
leave. If you’ve ever thought, “This should have healed by now, so why does
it still hurt?” you’re definitely not alone. In the United States, roughly
one in five adults lives with chronic pain that lasts for three months or
longer and, for millions, it significantly disrupts work, sleep, mood, and
relationships.

The tricky part? There usually isn’t just one cause. Chronic pain
is more like a crime committed by a gang of suspects: your nerves, your
immune system, your past injuries, your emotions, your stress level, and
even your job or home environment can all be in on it together.

In this in-depth guide, we’ll unpack the main causes of chronic pain, why
some people hurt more than others, and how factors you can’t seelike
stress, sleep, and moodcan turn the volume of pain way up. The goal is not
to scare you, but to make the puzzle of chronic pain feel more
understandable and a little less mysterious.

What exactly is chronic pain?

Doctors generally define chronic pain as pain that lasts
at least three months or that continues beyond the normal time for tissue
healing. It may:

• Follow an injury or surgery that seemed to “heal,” but the pain never fully faded.
• Be linked to an ongoing health condition, like arthritis or diabetes.
• Appear without a clear injury, as in fibromyalgia or some types of back pain.

Sometimes the pain is constant; other times it comes and goes in flares.
It can be sharp, burning, throbbing, electric, or just a relentless ache
that wears you down over time. Chronic pain isn’t just a symptom; for many
people, it becomes a long-term condition that needs its own treatment plan.

The big picture: chronic pain is biopsychosocial

To really understand the causes of chronic pain, it helps to step back and
use the biopsychosocial model. That’s a fancy term for a
simple idea: pain is shaped by three major categories of factors:

• Biological – injuries, inflammation, nerve damage, genetics, hormones, and changes in your brain and spinal cord.
• Psychological – mood, stress, anxiety, trauma history, coping style, attention, and beliefs about pain.
• Social – work demands, financial pressure, family support (or lack of it), sleep schedule, physical activity level, and more.

Chronic pain usually happens when these factors interact over time. You
might start with a clear physical triggerlike a back injury from lifting
something heavybut then poor sleep, fear of movement, job stress, and
nerve system changes all join the party. Before long, the pain you feel no
longer matches what you see on an X-ray or MRI.

Biological causes: when the body keeps sending pain signals

1. Ongoing tissue damage and inflammation

One of the most straightforward causes of chronic pain is
persistent inflammation or tissue damage. Common examples
include:

• Osteoarthritis – gradual wear and tear of cartilage in joints, leading to pain, stiffness, and swelling.
• Rheumatoid arthritis and other autoimmune diseases – the immune system mistakenly attacks the body’s own tissues, causing painful inflammation.
• Chronic low back pain – sometimes tied to degenerative disk disease, spinal stenosis, or facet joint arthritis.
• Chronic tendon or ligament injuries – such as persistent shoulder or Achilles tendon pain.

In these conditions, local damage and inflammation in joints, muscles, or
connective tissues keep activating pain nerves. Even when the damage is
relatively mild on imaging, the brain can interpret those signals very
loudlyespecially if other risk factors are present.

2. Nerve damage and neuropathic pain

When nerves themselves are injured or diseased, you can
develop neuropathic pain. This type of pain often feels
burning, shooting, electric, or like pins and needles. Common causes
include:

• Diabetic neuropathy – long-term high blood sugar damages small nerves, especially in the feet and hands.
• Post-herpetic neuralgia – nerve pain that lingers after a shingles infection.
• Pinched or compressed nerves – from conditions like herniated disks or carpal tunnel syndrome.
• Post-surgical nerve injury – sometimes nerves are cut or irritated during surgery and remain painful afterward.
• Chemotherapy-induced neuropathy – certain cancer drugs can damage nerves, leading to lasting pain.

In neuropathic pain, the nervous system starts misfiring. Nerves may send
pain signals spontaneously, or they may become overly reactive to mild
touch or temperature changes. It’s like your body’s electrical wiring has
been damaged and keeps sparking.

3. Central sensitization: when the nervous system turns up the volume

One of the key reasons chronic pain can hang aroundeven after an injury
has technically healedis a process called central sensitization.
Over time, repeated pain signals can cause the brain and spinal cord to
become hypersensitive. In other words:

• The “pain alarm” goes off more easily.
• The alarm rings louder than before.
• The alarm keeps ringing long after the threat is gone.

Conditions commonly associated with central sensitization include
fibromyalgia, chronic migraine, irritable bowel syndrome, temporomandibular
joint (TMJ) disorders, and some types of chronic pelvic or bladder pain.
People with central sensitization may hurt from things that usually don’t
cause pain at all, like light touch or gentle movement.

This doesn’t mean the pain is “imagined.” It means the nervous system has
been physically and chemically re-tuned, like a radio stuck on a station
with too much static.

4. Other medical conditions that drive chronic pain

A wide range of health problems can cause or contribute to chronic pain,
including:

• Fibromyalgia – widespread body pain, fatigue, and sleep disturbance, often tied to central sensitization.
• Chronic headache and migraine – recurrent pain episodes that can become frequent or daily.
• Endometriosis and chronic pelvic pain – tissue similar to uterine lining grows outside the uterus, triggering ongoing pain.
• Chronic abdominal or visceral pain – such as irritable bowel syndrome or painful bladder syndromes.
• Chronic post-surgical pain – pain that persists months after a procedure, sometimes from nerve changes or scar tissue.
• Cancer and cancer-related treatments – tumors, surgeries, and radiation can all cause persistent discomfort.

Often, people have more than one pain condition at the same time.
For example, a person with osteoarthritis in their knees may also have
fibromyalgia and chronic headaches, creating a complicated pain picture.

Psychological and emotional factors: how the mind and mood affect pain

Pain is always processed in the brain, which means what’s happening in your
emotional world matters. Psychological factors don’t “cause” pain out of
nowhere, but they can amplify or prolong it in powerful ways.

1. Stress, anxiety, and depression

Chronic stress, generalized anxiety, and depression are all strongly linked
with chronic pain. They can:

• Increase sensitivity of pain pathways in the brain and spinal cord.
• Disrupt sleep, which further lowers your pain threshold.
• Reduce motivation to move, exercise, or follow treatment plans.
• Fuel negative thoughts like “This will never get better,” which can increase suffering.

Not surprisingly, many pain clinics routinely screen for anxiety and
depression. Treating mood and stress isn’t “optional”it’s part of treating
the pain itself.

2. Past trauma and pain “memory”

Experiences such as childhood adversity, abuse, serious accidents, or other
trauma can change how the nervous system reacts to pain later in life. The
brain areas involved in fear, memory, and threat detection overlap heavily
with pain processing regions. When those circuits are on high alert,
everyday sensations can be interpreted as more threatening and painful.

Again, this doesn’t mean pain is “just psychological.” It means that your
life history can shape how your nervous system responds to new injuries,
illnesses, or stressors.

3. Thoughts, beliefs, and coping style

How you think about pain matters too. Certain mental patterns are
known to worsen chronic pain, such as:

• Catastrophizing – spiraling into worst-case scenarios (“This pain will ruin my life,” “I’m broken forever”).
• Fear of movement – avoiding almost all activity because you’re scared of making things worse.
• All-or-nothing coping – doing way too much on “good” days and then crashing for several days afterward.

Cognitive behavioral therapy (CBT), acceptance and commitment therapy
(ACT), and other psychological approaches can help people reframe these
patterns, lower stress, and reduce the intensity and impact of pain over
time.

Social and lifestyle causes: the world around you matters, too

Your body doesn’t exist in a vacuum. The environment you live and work in
can either help you recover from pain or keep you stuck.

1. Sedentary lifestyle and deconditioning

One of the sneaky causes of chronic pain is simply not moving
enough. When pain first appears, it’s totally normal to rest.
However, if rest turns into months of avoiding activity:

• Muscles weaken and stiffen.
• Joints lose mobility.
• Posture worsens.
• Even small physical tasks feel harder and more painful.

Over time, deconditioning itself becomes a cause of painespecially in the
back, neck, hips, and knees. That’s why graded, gentle movement is such a
key part of most chronic pain treatment plans.

2. Poor sleep and irregular schedules

Sleep and pain have a vicious two-way relationship: pain makes it hard to
sleep, and poor sleep increases pain sensitivity. Fragmented or short sleep
can alter how your brain processes pain signals and can worsen mood, making
pain feel even more overwhelming.

3. Work, stress, and financial pressure

High-stress jobs, long hours at a computer, physically demanding work, or
the constant worry of making ends meet can all contribute to chronic pain.
Stress hormones like cortisol influence inflammation, immune function, and
muscle tension. Think tight shoulders, clenched jaw, and tension headaches
that never quite go away.

4. Social support (or lack of it)

Pain is harder to bear when you feel alone or misunderstood. A lack of
support from family, friends, or employers can increase emotional distress
and make it more difficult to stay active, attend appointments, or follow
through with self-care. On the flip side, good social support can buffer
stress and improve outcomes.

Why does pain sometimes continue after an injury heals?

One of the most frustrating things about chronic pain is hearing, “Your
scans look fine,” while you’re still hurting. A few key mechanisms explain
why pain can live on after the original injury:

• Central sensitization – the nervous system becomes hypersensitive and continues to send strong pain signals.
• “Pain memory” circuits – networks in the brain that were repeatedly activated by pain become more easily triggered.
• Ongoing biomechanical issues – such as poor posture or altered movement patterns developed while you were protecting an injured area.
• Unresolved inflammation or micro-damage – low-grade tissue irritation that doesn’t show clearly on imaging.
• Psychosocial factors – chronic stress, fear, and mood disorders that keep the nervous system on high alert.

In many cases, it’s not that “nothing is wrong”it’s that the problem now
lives largely in how the nervous system and body are functioning, rather
than in one dramatic structural abnormality a scan can easily capture.

Common examples of chronic pain conditions

While the exact cause of chronic pain varies from person to person, these
are some of the most common chronic pain conditions:

• Chronic low back or neck pain.
• Osteoarthritis or rheumatoid arthritis.
• Chronic headache and migraine disorders.
• Fibromyalgia and widespread musculoskeletal pain.
• Diabetic neuropathy and other peripheral neuropathies.
• Chronic pelvic pain and endometriosis.
• Chronic abdominal pain, including irritable bowel syndrome.
• Chronic post-surgical or post-traumatic pain.

Many people don’t fit neatly into one diagnostic box. Instead, they have a
cluster of overlapping conditions and triggersanother reason a
“whole-person” approach to pain usually works better than focusing on a
single body part.

When should you seek help?

Don’t wait months or years to talk to a healthcare professional about
ongoing pain. You should seek prompt medical care if:

• Pain lasts longer than a few weeks and shows no signs of improving.
• Pain keeps you from sleeping, working, or managing basic daily tasks.
• You have red-flag symptoms like sudden severe pain, weakness, trouble walking, loss of bladder or bowel control, fever, or unexplained weight loss.
• Pain is accompanied by significant sadness, anxiety, or thoughts of self-harm.

A good pain management plan may include medications, physical therapy,
targeted nerve treatments, psychological therapies, lifestyle changes, or
complementary approaches like acupuncture or mindfulness. No single
strategy works for everyone, but most people do better with a combination
tailored to their specific mix of causes.

Important note: This article is for general information
and is not a substitute for professional medical advice. Always talk with a
qualified healthcare provider about your specific situation.

Real-world experiences: how chronic pain causes play out in everyday life

To make all of this more concrete, let’s look at a few real-to-life
scenarios (composite examples, not actual individuals) that show how the
causes of chronic pain often stack together.

Case 1: The “simple” back injury that didn’t stay simple

Imagine a 42-year-old office worker who hurts their lower back lifting a
heavy box. At first, it’s an acute injury: a strain to the muscles and
ligaments around the spine. They rest for a few daystotally reasonable.
But then they get scared of making it worse and stop most physical activity
altogether. Sitting hurts, standing hurts, moving hurts, so they do as
little as possible.

Over time, their core and back muscles weaken. They start sleeping poorly
because they can’t find a comfortable position, and that lack of sleep
makes their pain feel sharper and harder to tolerate. They worry constantly
about their job and finances, wondering if they’ll ever get back to normal.

A year later, imaging might show only mild wear and tearnothing dramatic.
But their nervous system has become highly sensitized, their muscles are
deconditioned, and chronic stress has rewired their brain’s “threat
detectors.” What began as a clear physical injury has evolved into chronic
low back pain driven by biological, psychological, and social causes all at
once.

Case 2: Nerve pain plus life overload

Now picture a 55-year-old with long-standing type 2 diabetes who develops
burning, tingling pain in their feetclassic symptoms of diabetic
neuropathy. The biological cause is nerve damage from years of high blood
sugar. But that’s not the whole story.

They’re also working two jobs, sleeping five hours a night, and feeling
overwhelmed trying to manage medications and doctor visits. Exercise feels
impossible when every step hurts, so they move even less. They may feel
guilty or frustrated with themselves, which adds emotional strain.

In this case, neuropathic pain is at the center, but chronic stress, poor
sleep, low physical activity, and emotional exhaustion all keep the pain
dial turned up. Addressing blood sugar alone won’t fully solve the problem;
the broader context needs attention too.

Case 3: Migraines, central sensitization, and invisible triggers

Consider a 28-year-old who’s had migraines since their teens. Over time,
the headaches become more frequent, then almost constant. They are bright,
capable, and drivenbut the pain keeps derailing work and social plans.

In the brain, repeated migraine attacks can lead to central sensitization:
the pain networks become hyper-reactive. On top of this, the person may be
skipping meals, drinking lots of caffeine, and pushing through long days on
a laptop. Stress from trying to “perform normally” despite constant pain
makes their nervous system even more reactive.

The causes of chronic pain here include inherited biology (a tendency
toward migraine), central nervous system changes, lifestyle factors
(irregular meals, screen time, sleep disruption), and pressure to keep up
with daily responsibilities. Once these factors are recognized, treatment
can shift from chasing each individual headache to calming the entire
system through medication, behavioral strategies, and lifestyle tweaks.

What these experiences have in common

These examples look very different on the surfacea back injury, diabetic
nerve pain, chronic migrainesbut the underlying themes are similar:

• There is usually a biological trigger (injury, disease, nerve damage, or inherited vulnerability).
• Over time, the nervous system changes, becoming more reactive to pain signals.
• Stress, sleep problems, mood, and lifestyle quietly shape how intense and persistent the pain becomes.
• Social factorswork, finances, family expectationseither help with recovery or push in the opposite direction.

Understanding chronic pain in this fuller way can be empowering. Instead of
feeling doomed by a single diagnosis or test result, you can start to see
multiple levers you might be able to adjust: movement, sleep, stress
management, emotional support, and medical treatments that target both the
body and the brain.

Chronic pain is complex, but it’s not random. The more clearly you
understand the causes in your situation, the better you and your
healthcare team can design a plan that actually fits your life.