Currently the front of my head is throbbing with the dull ache of a tension headache. I cannot pinpoint the source of the pain; it’s lingering somewhere behind my eyes and yet at the same time is gripping my forehead. It is deeply uncomfortable, and I’m waiting for the painkillers to kick in and relieve me.
As has become a common theme for my blogs of late, I’m counting on science to give some insight into this sensation. Why does tension, and stress, make your head actually ache? When you stop and think about it, it does seem a little peculiar that your brain feels like it’s been punched or used as a stress ball when you need some kind of stress relief yourself!
Although the causes for the many different headache types are either not known or only theoretical, the physical manifestation of the headache pain itself is universal. The culprit – the trigeminal nucleus.
This is a loosely defined brain area at the top of the spinal column and, due a number different nerves which have offshoots ending on the nucleus, it becomes the receptive centre of all potentially noxious stimuli to the top part of your body – and this has ramifications further up the nerve pathway.
The trigeminal nerve stimulates the nucleus. The largest of the cranial nerves, it has three separate branches snaking off of it which find their way toward the face, innervating the skin from your forehead to your eyes and nose, and even down to your jaw. The main role of these nerves is to detect heat and pain to your face. So when these nerves are activated, your experience pain in the skin on your face.
A headache can result directly from the activation of these nerves activating the trigeminal nucleus. But, importantly, your brain can also be tricked into thinking the nerves are activated. Because the trigeminal nucleus receives a multitude of different inputs from various nerves running up the spinal column, sometimes when the nucleus is activated by a nerve coming from the body it is misinterpreted as a pain signal from the face – and we experience a headache!
A tension headache results when prolonged contractions of the muscles through your shoulders and back activate these nerves running into the trigeminal nucleus, making your brain think that there is a constant pain in your face, and that horribly familiar ache of a tension headache results.
I think it’s actually making my headache worse just thinking about it! But on a lighter note, for all you physiology geeks out there, here is a wonderfully nerdy song about the physiology of an ice cream headache to cheer you up….