1. If the individual parts of the compound subject are joined by and, always use a plural verb. 2. If the individual parts of the compound subject are joined by or or nor, use the verb form (singular or plural) which will agree with the subject closer to the verb.
Headaches in the back of the head may be caused by a variety of ailments and injuries. Chronic headaches in the back of the head -- also known as occipital headaches -- are often variants of tension-type headaches or migraines. New-onset occipital headaches are a more urgent concern. Possible causes include blood vessel abnormalities, nerve disorders and serious traumatic injuries.
Cluster headache. Cluster headache (CH) is a neurological disorder characterized by recurrent, severe headaches on one side of the head, typically around the eye. There is often accompanying eye watering, nasal congestion, or swelling around the eye, on the affected side. These symptoms typically last 15 minutes to 3 hours.