If you have ever gotten a bug bite or poison ivy, you may know this feeling very well. You may also just randomly have an urge to scratch yourself but why? This is a really interesting phenomenon that scientists don’t know everything about, but here is what we know so far.
The sensation of itching is produced from a molecule called neuropeptide natriuretic polypeptide b, or Nppb for short. It is normally released by the heart to control sodium and blood pressure. Yet, for some reason it is the same molecule that activates the electrochemical signal from the skin to your brain. When a trigger occurs on your skin, the Nppb molecule cross the synaptic gap to adjacent nerve cells which carry the signal through the spinal cord to the brain. Some things that make you itch include bug bites, poison ivy, dry skin, jewelry, sunburns, stress and anxiety, as well as certain types of diseases.
Since the Nppb molecule is a neurotransmitter that activates the signal to itch, it means that there can be a drug developed to block the receptor site (to stop the itching sensation), but it is problematic because the same molecule is used for regulating important bodily functions. It is in the class of nerve cells (TRPV1-expressing) that also includes pain and heat. So when you scratch, you cause temporary pain in the area that overtakes the signals of itchiness. You could also apply some extreme heat, which would also cause the sensations of itchiness to diminish.
Although scientists don’t know much more about the causes of itchiness and how to effectively stop it, there are both physical and emotional symptoms for it. If you find yourself itching when you’re studying of just at random times, it may be a sign that you are feeling really stressed and anxious. It could also mean that you have some small particles on your skin that your body deems potentially harmful. Thus, scratching will effectively remove them from your skin and your body will feel a relief from it.