Temporal arteritis, also known as giant cell arteritis (GCA), is a condition which causes inflammation on the inside of some blood vessels (arteries). It is called 'giant cell' because abnormal large cells develop in the wall of the inflamed arteries. The arteries commonly affected are those around the head and neck area. One of the arteries that is commonly affected is the temporal artery. (You have a temporal artery on each side of the head. They are under the skin to the sides of the forehead - the temple area.) Therefore, the condition is sometimes called temporal arteritis. Several arteries may be affected at the same time.
This is a companion discussion topic for the original article at https://patient.info/eye-care/visual-problems/temporal-arteritis-giant-cell-arteritis