1 An adenoma is a part of the gland that has walled itself off from the rest of the gland, forming noncancerous (benign) lumps that may cause an enlargement of the thyroid. Not all adenomas produce excess T-4, and doctors aren't sure what causes some to begin producing too much hormone.  Thyroiditis.
Scratching Itchy Skin Causes Brain To Release Hormone Serotonin, Intensifies Itchy Sensation. While a good scratch may temporarily relieve you of your itch, it actually stimulates serotonin in the brain that intensifies the itchy feeling.
Depending on the cause, itchy skin can be short-term and disappear quickly, such as when itching occurs due to a buildup of dead skin cells. For example, if you feel itchy all over and live in a dry climate, you may have âwinter itch,â which is caused by the lack of moisture in your skin.