[moonfire (OP)]

Is it the lack or not enough oxygen to the brain..?  Constricted blood vessels? 

 []

[Hadrian]

A headache is a symptom, not a disease. A headache is rarely the symptom of a serious illness, but severe or frequent headaches can be exhausting and can affect daily life.

There are three basic types of headaches. The vascular headache occurs when blood vessels in the head enlarge and press on nerves, causing pain. The most common vascular headache is the migraine.

The second type of headache is the muscle contraction headache, which results when the muscles of the face, neck, or scalp contract and tighten. A tension headache is an example of a muscle contraction headache.

The third kind of headache is the inflammatory headache. Such a headache is the result of pressure within the head. The causes range from relatively minor conditions, such as sinusitis, to more serious conditions, such as brain tumors.

[moonfire (OP)]

Thanks Hadrian!  I had heard about the headaches with blood vessels do something...aagghh...I was trying to remember that when I was going to school to be a Nurse....But I think your sheepie probably has one with all that jumping up and down he does...by the way, what is your sheepie's name?  LOL