Why It Feels So Good to Scratch an Itch
Each person on the planet feels the need to scratch something on their body at least once a day. By satisfying this need, we are rewarded with pleasant sensations that make us scratch the itch again and again.
5-Minute Crafts studied this question carefully and would like to tell you about what itching is and why it feels so good to scratch an itch.
What itching is
From a medical point of view, itching is an unpleasant irritating sensation on any part of the skin. Despite the fact that all of us know how itching feels, its mechanism is one of the least understood and studied in the world of dermatology.
The sensation of itching can be seen as an evolutionary advantage. The skin is constantly in contact with the outside world, therefore, in the process of evolution, humans have developed unique protective mechanisms that allow our skin to remain intact. Simply put, itching is the body’s way of letting the brain know quickly that something potentially dangerous is irritating the skin.
There are 4 main clinical categories of itch:
- Caused by irritation or inflammation on the skin
- Caused by brain disorders
- Caused by damage to the central or peripheral nerves
- Caused by diseases that affect organ systems other than the skin
What causes itching
There are many things that can cause itching. Sometimes it’s something obvious, like a mosquito bite, and sometimes it’s a spontaneous and inexplicable desire to scratch the skin here and now. Here are just a few of the most common things that can cause itching.
- An allergic reaction to food or medication
- Dry skin
- An insect bite
- Skin diseases
- Liver, kidney, or thyroid disease
- Pregnancy
- Burns
- Diseases of the nervous system
It’s important to understand that for the most part, a one-time desire to scratch a particular area of the skin is not caused by something serious. However, if the itching doesn’t go away for a long time, this can be a reason to consult a doctor.
Where itching is formed
It was believed in the past that itching is a form of pain, as it activates the receptors in the epidermis responsible for informing the brain about painful sensations on the skin. However, later it was found that our central nervous system is able to distinguish between these 2 sensations, despite the fact that they have common neural pathways.
Scientists conducted a lot of experiments and eventually came to the conclusion that itching is formed in the parabrachial nucleus (for comparison, the thalamus is responsible for pain).
Why it feels so good to scratch an itch
Scratching a particular area of the skin is often rewarded with incredibly pleasant sensations. Sometimes they are so strong that a person continues to scratch the same place until serious damage occurs.
The reason for such destructive behavior is the gastrointestinal tract. This statement may seem absurd, but the gastrointestinal system is also responsible for the production of serotonin along with the brain. And serotonin is the main reason why we feel so good when scratching.
However, this pleasant feeling has a downside: the formation of a vicious cycle consisting of itching, scratching, pleasure; itching, scratching, pleasure; and so on. As a result, we get painful lesions on the skin.
Scientists easily explain the nature of this process: when we scratch, our sensations are mixed with pain, and the brain releases serotonin to suppress it. Serotonin then binds to certain receptors on certain neurons that cause the itchy sensation again.
A few facts about itching
- Itching is as contagious as yawning or laughing. Scientists proved this by the example of mice that start scratching if they see other mice scratching.
- The more you scratch, the more you want to keep scratching.
- The area on the skin that brings the most satisfaction during scratching is the ankle. This was proved through research. And you probably just scratched your ankle to check it out.