Does it feel itchy on your scalp, which is the skin close to your hair? It could be due to lice. Lice are only spread through direct hair-to-hair contact. If you have lice, you should treat it as soon as possible. You do this yourself at home.
If your skin itches in several places, especially your hands, you may have scabies. Scabies is caused by a small insect that lives under the skin. It is spread through direct skin-to-skin contact. If you have scabies, you need treatment as soon as possible.