why do we itch

Itching, also called pruritus, is a sensation caused by irritation of skin cells or nerve cells associated with the skin. It serves as a protective mechanism that alerts us to potential dangers such as irritants, allergens, or parasites on the skin. This irritation activates specialized nerve endings called pruriceptors, which send signals to the spinal cord and brain, triggering a scratching reflex. Scratching an itch feels good because it produces mild pain signals that temporarily distract the brain from the itch. These pain signals also release serotonin, a neurotransmitter that feels pleasant but can reset the itch signal, sometimes creating a cycle where itching leads to scratching and scratching leads to more itching. The causes of itching can be diverse, including dry skin, allergic reactions, insect bites, infections, or underlying systemic diseases. Chemicals involved include histamines, neuropeptides, and other inflammatory mediators that stimulate the nerve fibers responsible for itch sensation. While scratching offers temporary relief, it can also worsen the irritation and potentially damage the skin, causing inflammation or infection. Hence, itching is both a signal of a problem that needs attention and a response mechanism that tries to protect the body.