Chronic pain - why pain sometimes persists, and how to find relief from it

Chronic pain can wear you down. It can make you feel a sense of loss by forcing you to give up the things you love. It can also be incredibly frustrating because doctors often can’t tell you what’s causing it.

Understanding your pain and how to get rid of it requires looking at the parts of your body that create pain and how they affect its intensity.

How pain is created

Body sensors

Think of a body sensor as a little button in your body that can be pushed to send signals between your body tissues and your brain. The more (or harder) the button is pressed, the more messages it sends.

Millions of sensors in your body monitor different stimuli, like changes in temperature (hot or cold), pressure, stretch, motion, and chemicals. The sensors are continuously firing, sending messages about what's happening in their vicinity to your brain via your spinal cord.

For example, the sensors monitoring how much your muscles and tendons stretch will be quiet while sleeping (because their buttons aren't being pushed). But they will fire often during a yoga class because of all the stretching your muscles will do.

The subconscious brain

Your subconscious brain is potent. It is responsible for several unconscious functions like breathing, heart rate, blinking, and reflexes.

This part of your brain also:

• Constantly processes all the stimuli (signals from your environment) your body senses
• Works like a filter, deciding which messages are essential and should be acted upon and which can be ignored
• Adjusts your actions to balance and keep the messages it receives within a specific range or threshold

Everyone's subconscious brain has a set threshold for what it considers safe versus potentially dangerous levels of stimulation for pressure, stretch, temperature, etc.

Your brain will only take notice and create pain if the stimulation level increases above the set threshold.

Contrary to what many people believe, no pain sensors measure or create pain in your body. Instead, it’s your subconscious brain that creates pain to get your attention and help keep you within the safe zone of your threshold.

Interestingly, these thresholds can fluctuate and are like moving targets. This is because your brain raises and lowers them in response to several factors, which we'll discuss in the following sections.

The purpose of pain

Why does your subconscious brain create pain? Your brain is concerned with keeping you safe. Pain is your brain's protective mechanism to alert you to potential danger. It keeps you away from harm and helps you take the right action to protect yourself from further injury.

For example, if you touch a hot stove and your skin temperature increases too much, you will likely feel pain. Also, if you suddenly change direction while running, your ankle muscles may stretch too quickly, making you feel pain.

In these cases, pain warns you to move away from the hot stove and stop you from allowing your ankle to twist too far.

Pain intensity does not equal injury or injury severity

In an ideal situation, pain is created when you injure yourself and reduces as your injury heals.

But, researchers have observed that similar-looking injuries on an MRI can have different pain pictures.

This means that even with the same structural changes visible on a scan, some people experience severe pain, while others have mild or no pain at all. In some cases, pain also persists long after an injury heals.

Why does this happen?

Judgment and perception of threat

When your brain is trying to judge how dangerous a situation is and, thus, what level of pain it should create, it doesn't just look at tissue damage.

It also tries to predict what impact an injury may have on things that are very important to you, like your job, finances, social and family life, or sport.

To do this, it assesses your previous experiences in similar situations, your beliefs about what’s happening, and new information you’ve gathered from the people and things in your environment.

Your brain can amplify or dampen your pain based on these factors.

For example, your brain may amplify your pain if:

• A previous injury resulted in you missing out on an important event,
• You believe you will never get better
• Someone says you will never run again because of it

But the opposite is also true. Studies show that pain levels can immediately reduce when people receive a favorable diagnosis or are told an injury is not as bad as they thought.

In these cases, the injury didn’t suddenly change. Instead, these people gained a new understanding of their situation, which altered their perception of their injury.

Due to this, their brains rated it as less dangerous, lowering the threat level and decreasing their pain intensity.

Stress hormones

The brain also monitors the stress hormone levels circulating in your blood. These hormones are released in response to stressful situations. For example, work stress, an argument with a partner, or losing a loved one.

When your brain detects increased stress hormones, it assumes you’re in danger. As a result, it can create pain or increase your current level of pain to help protect you.

Programmed to create chronic pain

Evidence suggests that if you feel pain for longer than 3 months, your nervous system adapts and becomes more efficient at creating pain.

Some of the changes that happen when you have persistent pain include:

• You develop more sensors in the injured area
• The sensors in that area fire easier and quicker (in response to lower-level stimuli)
• Your spinal cord sends signals faster and amplifies them
• Your brain overestimates the threat of the injury, creating pain levels that don't match the tissue damage level (which can continue long after healing has taken place)

As you can see, your nervous system becomes primed to create pain quickly and intensely when you have persistent or chronic pain. What does this look like in practice?

Think back to before you were injured. You likely felt many niggles and pain signals during a run or heavy workouts. These helped you gauge how much you could push yourself without any trouble.

These little warning signs probably appeared in all parts of your body but disappeared as soon as you finished the exercise or activity.

With chronic pain, your brain becomes used to worrying about an injury occurring or worsening.

So, it sends you these warning signs often and long before an injury occurs. Even with the slightest amount of activity or effort.

Sometimes, just the idea of moving your body or hearing the word "exercise" can make you feel pain.

How to reprogram chronic pain

The good news is that the changes mentioned above are reversible, even if you’ve had persistent pain for more than 3 months.

It takes patience and perseverance, but your sensitized "alarm system" can calm down over time.

First, you need to remember that pain does not equal tissue damage. However, it doesn't mean you should push through pain or ignore it.

If you haven't convinced your subconscious brain that moving is safe yet, it will increase your pain.

Your primary aim should be to reassure your subconscious that movement is safe. Gently reinforcing that it doesn't have to protect you so aggressively.

You can do this in a combination of ways:

1. Moving within acceptable pain levels

Research shows that various exercises and activities can help reduce and reprogram pain.

This includes walking, cycling, swimming, stretches, core workouts, strength training exercises, yoga, and Pilates. What is appropriate for you, will depend on the area of the body you have pain in. Your physical therapist can help guide you on this.

The key is to start at a level that does not feel threatening to you (i.e., your subconscious brain) and then slowly increase it as you get used to it.

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2. Expect flare-ups

Recovery never progresses along a straight line. Instead, it looks more like a squiggly line of progress and setbacks.

So, when you experience a flare-up, remember that pain does not equal injury and allow it time to settle.

You can find practical tips on how to do this in our article "How to handle painful injury flare-ups."

Over time you'll notice your progress periods becoming more frequent and longer. Flare-ups will be less intense and will happen less often, and your pain will calm down quicker.

3. Reduce your stress hormones

If you think that high-stress levels may be impacting your pain response, there are steps you can take to reduce your stress hormone levels.

These include:

• Changing your work habits
• Asking for help to resolve difficult situations
• Talking to someone if you feel overwhelmed
• Getting enough quality sleep
• Taking time to rest and relax
• Doing breathing exercises
• Practicing meditation and mindfulness

4. Check your thoughts

Your thoughts and beliefs can have a powerful impact on your physical well-being too.

That’s why it’s crucial to check in with yourself often and reflect on your beliefs about your injury that may be triggering your threat system.

Common unhelpful beliefs identified in the research include:

• "If I get pain, it means I have damaged something"
• "Severe pain must mean that I have something seriously wrong"
• "I will never run or play sports again"
• "If I start exercising, it will hurt more"
• "Movement will injure me"

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In summary

• Pain does not always equal injury or match injury severity - you can have a minor injury with lots of pain, a major injury with very little pain, and even no injury with severe pain
• Your subconscious brain creates pain when it thinks you're in danger - it will amplify or dampen the pain intensity according to the level of threat it perceives
• Pain persists as long as your subconscious feels you're in danger
• Pain will decrease when your subconscious believes the danger has passed
• Pain is multidimensional - your subconscious brain looks at your stress hormones, memories, and beliefs, then tries to understand the potential impact of the injury on your life, before deciding on a threat level to assign and how much pain to create to protect you
• When you've had pain for over 3 months, your nervous system usually becomes sensitized, causing a heightened pain response (your brain creates pain quickly and more intensely)
• You can reverse this over-sensitivity by showing your subconscious that movement is safe, gradually increasing your activity level, and addressing any stressors and unhelpful beliefs contributing to it
• "Mind over matter" will not work to reduce your pain because your subconscious brain does not trust your conscious brain to make responsible decisions to keep you safe