Earlier humans considered pain as an evil or a demon or magic. The Greeks and Romans were the ones to advance the theory of sensation, the idea that the brain and nervous system play a role in the perception of pain. Later, Leonardo da Vinci and his contemporaries believed that brain is the central organ for perception or sensation. They also stated that the spinal cord transmits sensations to the brain.
Now you must be wondering what exactly happens in our body that causes pain?
Well, there are microscopic structures called pain receptors throughout our body. When a painful event happens, the damaged area releases chemicals, which in turn excite the nerve fibers. They transmit the pain signals to the spinal cord where the pain intensity is filtered and modified and then sent to the sensory cortex of brain through a bundle of nerve fibers which makes the person perceive the pain.
How is the pain treated?
The body’s own pain killers have proven to be the most effective pain relievers. The brain may signal the spinal cord to release the pain killers.
One way of relieving pain from outside the body is by inhibiting the hormones like prostaglandins which stimulate the nerve at the site of injury and cause inflammation and fever. Certain drugs like NSAIDs act against these hormones by blocking the enzymes required for the release of these hormones.
How does the pain killer act in the body?
The mechanism of pain killers (analgesics) is inhibition of prostaglandin synthesis. This reduces pain and inflammation.
What is drug tolerance?
When a person needs higher doses of the drug as the person’s reaction to the drug reduces though the dose at the effect site is the same is known as drug tolerance. This means larger doses of the drug is required to achieve the same effect. This occurs due to continuous intake of the drug.
When a specific molecule is present in higher levels in the brain through regular use of a drug, the brain adjusts accordingly. It changes the level of the chemicals which it produces to compensate the increased levels of the drug taken.
The best way to prevent tolerance is to reduce the use of drugs.