Pain is an unpleasant sensory and emotional experience, but it is also the body’s way of warning you that something isn’t right. No one enjoys pain – especially back or neck pain – yet there is value in the fact that the body has a way of signaling that something is wrong.

Experiencing pain is not enough on its own. Understanding the different types of pain, how to classify it, and what each type means helps you grasp the nature of your problem and how to treat it. This article covers the differences between short and long-term pain, as well as mechanical, chemical and neurological pain.

What Is Pain?

Pain is an unpleasant and often disruptive feeling that can be felt in the body. It can come on gradually, or it can start mild and rapidly intensify. Whatever the case, pain tends to make you want to avoid physical activity for fear of causing more discomfort.

People feel pain when specific nerves called nociceptors detect tissue damage and transmit that information along the spinal cord to the brain. Touching a hot surface, for example, sends messages to the brain in less than a hundredth of a second – before we are even consciously aware of it – hopefully fast enough to pull away before damage is done. The brain’s interpretation of these signals, and the efficiency of the spinal-cord-to-brain connection, shapes how well we handle pain.

Some of the most common causes of pain include:

Headache
Toothache
Sore throat
Stomach ache or cramping
Muscle cramps, strains and sprain injuries
Cuts, burns and bruises
Joint pain such as neck and back pain

The Difference Between Acute and Chronic Pain

One of the first steps to understanding your pain is classifying it as either acute or chronic. Acute pain has a sudden onset triggered by something specific. It is usually described as sharp, shooting, burning or tearing. Fortunately, acute pain doesn’t last long and should resolve within about six months. Examples of acute pain include:

A sprained or twisted ankle
Pain following surgical procedures
Broken bones
Burns or lacerations

Chronic pain, on the other hand, lasts longer than six months. This type of pain persists even after the original source of damage has healed, often because the nerves continue firing as if you are still injured. Some people experience chronic pain without ever having a specific injury. Examples of chronic pain include:

Headache
Arthritis
Cancer-related pain
Nerve pain
Back pain
Pain linked to PTSD or adverse childhood experiences

The Difference Between Mechanical and Chemical Pain

After determining whether pain is acute or chronic, the next step is classifying it as mechanical, chemical or both.

Mechanical pain is connected to how you move or the position of your body. If you bend a finger back as far as it will go, you will likely feel mechanical pain – and when you release it, that pain changes or diminishes. This happens because of mechanical stress placed on tissue by forces like bending too far, creating discomfort even where there is no actual damage.

Mechanical pain can be acute, as with bending and releasing a finger, or chronic, where the pain doesn’t change once the stress is released. An example of chronic mechanical pain is low back pain from poor posture, where ligaments, tendons and muscles become deranged. This takes longer to correct than acute mechanical pain. Examples of mechanical injuries include:

Herniated discs
Dislocations
Meniscal or labral tears
Scar tissue or adhesions
Muscle, ligament and tendon injuries
Pain produced by abnormal posture and alignment

Specific movements or exercises that change your pain are a good sign that the pain is mechanical. Pain that doesn’t change with movement is more likely chemical.

Chemical pain involves inflammatory chemicals rather than damage to the tissue itself. It is complex and usually follows an acute injury, occurring as a side effect of the immune system’s response. If you’ve ever stubbed a toe, sprained an ankle or cut a finger, you’ve experienced chemical pain. It is typically described as a constant throbbing that doesn’t change with movement. If your pain comes and goes, shifts sides or moves around, it is likely not chemical – though it is entirely possible to have mechanical and chemical pain at the same time.

When someone herniates or injures a spinal disc, inflammation immediately surrounds the surrounding ligaments, tendons, muscles, joints and nerves. Most disc injuries are mechanical in origin, and the path toward addressing them is also mechanical. But when pain is both mechanical and chemical, relief may not come right away because the chemical factors are still present.

Treating Mechanical and Chemical Pain

Mechanical pain responds to mechanical treatment – changes in position and improvements in movement and posture. Treatment is targeted to a specific joint or tissue to change its current mechanical position or property. With a shoulder dislocation, severe pain may require strong pain management, but once the shoulder is relocated, much of the pain resolves because the mechanical stress is removed.

Chemical pain responds well to more targeted care such as anti-inflammatory treatments or immune modulation. These approaches either reduce inflammation or alter the injury’s ability to transmit pain signals to the nervous system. Given how multifaceted diagnosing and treating pain can be, it helps to work with a multidisciplinary provider who has the expertise and tools to address the various causes and presentations of pain.

Learning to Move Again

The thought of moving again can be intimidating if movement was painful before, but movement itself is one of the best ways to reduce pain. Here is how to get started:

Focus on breathing. Taking deep breaths from your diaphragm can quiet the nervous system.
Start with small movements. Choose movements you can perform for one or two minutes, then gradually branch out to new ways of moving.
Focus on one section of your body. Use mindfulness to feel the gentle movement of one part of your body, then let it go and move to another. This helps release the fear of feeling pain.
Graduate to positions or activities that previously triggered a pain response. This trains the brain away from pain using specific imagery and helps restore a normal response.