An itch, also known as pruritus, is an unpleasant and annoying sensation that makes you scratch your body. It can happen due to various reasons such as parasitic mites, dry skin, insect bite, disease, allergies, and sometimes, it happens for reasons that still remain unknown.
Just as the immune system functions as an internal defense mechanism, our skin has a defense system of nerves that makes us aware of annoying things that touch our body and our naturally itching response equips us to dislodge any potential threat that can be crawling on our skin like a harmful insect. But to answer the question: what exactly makes us feel an itch? It turns out that humanity still don’t know all the reasons behind it despite the magnificent advancements in modern medicine, but researchers experimenting on mice may have found the culprit. Yes. Study shows that a sub-class of nerves that are linked with pain transmits itch signals in mice.
These nerves generate a molecule known as Natriuretic Polypeptide B that carries the signal up through the spinal cord to the brain and creates the itchy sensation. Since mice and people share similar biology, research suggests that people also have these nerves too. But another vital question is: why do we scratch our itches? It is because when the neurons in the spinal cord send the pain signal instead of an itch signal to the brain, it releases a neurotransmitter known as serotonin, a chemical resulting in making us feel good as the pain reduce, so we keep feeling better as we scratch the itch, till we stop feeling it totally.