An Occipital Nerve Block is an injection of numbing medication and steroid around the greater and lesser occipital nerves that are located on the back of the head just above the neck area.  The steroid injected reduces the inflammation and swelling of tissue around the occipital nerves.  This may in turn reduce pain, and other symptoms caused by inflammation or irritation of the nerves and surrounding structures.  Typically, headaches over the back of the head, including certain types of tension headaches and migraine headaches, may respond to occipital nerve blocks.