Science of Pain

How do we feel pain?

Pain is a complex experience. It is not same as harm to the part of body. It involves both sensory and emotional components. It is the body's way of signalling to brain that something is wrong and needs attention.

Pain causing event like heat, pressure, etc is detected by specialized nerves called nociceptors, which are located throughout the body. These nerves send pain signal to brain via spinal cord. The brain evaluates severity level and takes necessary emotional and physiological actions.

How the feeling of pain is controlled?

The pain severity can be modulated using opioids. Opioids are a class of drugs, also known as narcotics, that are commonly prescribed for relief from moderate to severe pain, such as pain associated with surgery, cancer, or injury. However, they can also be highly addictive and have other ill-effects.

The pain communication path from nociceptors to brain involves neurons – senders and receivers. Opioids bind to the receptors of receiver neurons, known as opioid receptors. As receptors get blocked by these opioids, so does the transmission of pain signal to brain. Opioids also activate other neural pathways in the brain that produce feelings of pleasure, euphoria, and relaxation. These effects contribute to the pain relief experience.

Natural opioids are derived from the opium poppy plant, and include drugs such as morphine and codeine. Synthetic opioids, such as fentanyl and oxycodone, are chemically produced and designed to have similar effects to natural opioids. 

Our body also produces opioids (endogenous opioids) such as endorphins. As part of its pain management actions, brain releases Endorphins.

What is Placebo Effect?

When a patient believes that a treatment will be effective, this triggers release of endorphins and other natural painkillers in the body, leading to a reduction in pain and an improvement in other symptoms.

Surprisingly in many cases, this belief of patient is found to make the treatment work even if it is fake. This fake treatment that provides relief due to patient beliefs is called as Placebo. The relief caused by placebos is refrred to as Placebo Effect.

Placebo Effect also causes release of other neurochemicals like dopamine (signalling pleasure), oxytocin (cuddle hormone), which have a strong calming and analgesic effect.

Neuroscience of Placebo Effect

Experiments using brain imaging suggest that the brain has a real response to the expectations and context surrounding placebos which have an effect on the body.

Growing Influence of Placebos

Researchers are continuing to investigate the mechanisms behind the placebo effect and how it can be harnessed to improve health outcomes.

While it is not a substitute for effective medical treatment, the placebo effect can be used to enhance the benefits of other treatments and improve overall outcomes for patients.

In fact, the placebo effect is seemingly getting bigger which makes these findings all the more important.