The 8 Questions of Pain

Pain is your body’s early warning system. It protects you from the world around you, and from yourself. These detectors are specialized nerve cells called nociceptors that stretch from your spinal cord to your skin, your muscles, your joints, your teeth, and some of your internal organs. Just like all nerve cells, they conduct electrical signals, sending information from wherever they are located back to your brain. But, unlike other nerve cells, nociceptors only fire if something happens that could cause or is causing damage.

For example, gently touch the tip of a needle. You will feel the metal, and those are your regular nerve cells. But you won’t feel any pain. Now, the harder you push against the needle, the closer you get to the nociceptor threshold. Push hard enough, and you will cross that threshold and the nociceptors fire, telling your body to stop doing whatever you are doing.

2. How does low pain tolerance and high pain tolerance work?

Pain is actually a very complex process. See, what you experience as pain happens in your brain, not your nerves.

Nociception (literally “harm perception”) is the process of a pain-sensitive nerve detecting a toxic stimulus and sending a message back to the brain. All peripheral nerves terminate at the spine and pass the message on to the spine and up to the brain. But this does not always result in “pain”.

Firstly, there is what is called the pain gate. This is a spinal mechanism whereby the spine shuts out one pain stimulus in favor of another – it is why rubbing a wound lessens the pain. The spine is literally blocking a portion of the pain stimulus in favor of the less painful rubbing.

Secondly, there is the brain itself. Whole PhDs have been written on this, but the summary is the brain decides how much pain to feel based on context. Emotional state, prior experience, concentration and even language itself all have an impact on pain perception. It’s why an athlete might break their ankle but finish a race, while a person with a bad back experiences more pain when he’s having a bad day, or why injuries always seem worse at night when you have nothing else to focus on.

Pain tolerance is a mix of all these factors. Some people have alternative nociception pathways (there is even a congenital syndrome wherein a person has none) at all, some have excellent mental strategies for coping and some people literally just have better things to do. Some poor people have experienced something worse and can contextualize it differently. Pain is technically impossible to objectively measure – no two people will experience the same harmful event the same way.

3. Do people really have different pain thresholds?

There are people who barely make a noise from an injury that may cause someone else to scream aloud. Being invulnerable to pain might sound great, but it is not always. If you cannot feel pain, you could get hurt, or even gravely hurt yourself and never know it. Pain is generally known as your body’s early warning system. But an individual’s pain threshold is not set in stone—that’s why doctors ask for you to rate your comfortability or pain experience from 1-10.

When cells are damaged, they release a chemical called arachidonic acid and two enzymes in our body called COX-1 and COX-2 convert this arachidonic acid into prostaglandin H2, which is then converted into a bunch of other chemicals that do a bunch of things, including raise your body temperature, cause inflammation and lower the pain threshold. Certain chemicals can tune nociceptors, the sensory receptors that fire when experiencing the pain-causing stimuli, lowering the individual’s threshold for pain. When cells are damaged, they and other nearby cells start producing these tuning chemicals immensely, lowering the nociceptors’ threshold to the point where just a touch can cause pain.

4. Why do we sometimes get brief pains at random parts of our body?

The phenomenon is called “referred pain”. It occurs when the pain you feel in one part of your body is actually caused by pain or injury in another part of your body. For example, an injured pancreas could be causing pain in your back, or a heart attack could be triggering pain in your jaw.

5. What do pain relieving drugs exactly do and what is the difference between Advil and Tylenol?

There are several types of OTC pain relievers. Advil (ibuprofen) belongs to a class known as NSAIDs. Non-Steroidal Anti-Inflammatory drugs. Some other well-known NSAIDS are naproxen sodium (Aleve) and Ketorolac (Toradol). NSAIDs work by stopping the body’s inflammation response. These drugs inhibit certain enzymes that produce inflammation/pain at the injury site, as well as fever. Essentially, NSAIDs lessen the body’s physical response to an injury. Acetaminophen (Tylenol) on the other hand, works differently. The exact mechanism of action of acetaminophen (Tylenol) is not known. It does not reduce inflammation in injuries and appears to only inhibit enzymes in the brain. Tylenol is not actually doing anything physical to the injury site. So, while NSAIDs stop swelling and pain at the injury site, Tylenol appears to stop your brain from recognizing the pain.

6. Why does massaging a sore muscle bring pain relief, but touching an acute injury hurts?

A muscle’s natural state is to be relaxed. Contraction causes movement. A “sore” muscle is in a contracted state even when it should not be. Massaging it causes the muscle fibers to relax (heat will do the same thing) which can relieve the soreness.

An acute injury usually involves injury to nerves. Any pressure on these injured nerves will stimulate the nerve which causes pain.

7. If the colon has no pain receptors, why does trapped gas hurt so much?

There are muscle fibers on the outside of your colon that help with peristalsis. Peristalsis is a series of wave-like muscle contractions that moves food to different processing stations in the digestive tract. The process of peristalsis begins in the esophagus when a food is swallowed. A gas filled colon can make these fibers stretch much more and that is where the pain is coming from.

8. What is a Pain Pharmacologist?

In the medical context – for example, if you are going to a doctor – if someone is being called a “pain pharmacologist” then they are going to be a pain management specialist with a pharmacy degree. One of their roles is to regulate opioid use and to find non-opioid alternatives to help manage your pain.