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.
Many things can make your skin itch. Dry skin, eczema, and hives can cause itching all over your body. Contact dermatitis is another cause of all-over itching. You can get this condition after your skin comes in contact with something that irritates it, such as a strong laundry soap or a body lotion. You might feel itchy in only a few parts of your body.