The most common headaches are tension headaches, migraines and cluster headaches. These are considered primary headaches as they are headaches that are due to the headache condition itself, and not due to another cause.
Tension headaches are characterized by a pressure type of pain that can affect the forehead, or the top of the head, or the whole of the head. Most commonly if feels like a tight band around the head. The headaches usually respond to common analgesics.
Migraine headaches are characterized by a throbbing pain that often affects one side of the head and it can spread to the other side during the same attack. There can be warning symptoms prior to the pain, such as alteration of vision such as seeing bright lights, zig-zag lines, color changes, blurring vision, etc. Such warnings are called Aura. They can last from a few minutes up to an hour and then the head pain starts. During the headache there can be nausea, vomiting and sensitivity to light, noise or smells. Migraines can respond to common analgesics but usually they require a more specific treatment (triptans).
Cluster headaches occur in cyclical patterns, or clusters, and are one of the most painful types of headache. A cluster headache commonly awakens you in the middle of the night with intense pain in or around one eye on one side of your head. Such headaches require specific treatment.