正文
When our body sustains a wound, a number of chemical and physical processes almost immediately begin to protect our bodies from infection and pain. A wound will initially bleed, flooding the space with chemicals and fluids to clean the area and set the stage for healing to begin. Following this, the wound will become inflamed, which is a sign that white blood cells have reacted to the potential for infection; additional cleansing of the wound happens at this point, in addition to preliminary repairs on the skin bed.
Four Stages of Healing (Photo Credit: designua / Fotolia)
Those first two stages (bleeding and inflammation) are typically considered “painful”, but in the third stage, the tissues begin to regrow, blood vessels are repaired, and a scab begins to form over the healing wound. This part of the healing process is where the itchiness begins, and to understand an itch, we need to look at the nerves.
Chemical and Physical Causes of an Itch
Every square inch of our skin is connected to nerves, which provide us with our sense of touch and sensitivity to external stimuli. There are also many itch-specific nerve fibers located on our body’s largest organ. These fibers tell our central nervous system that something is irritating the skin in a certain spot, with the intention of eliciting a response from the body (scratching the itch).
