I am writing this article while experiencing quite a disruptive and quite rude uninvited headache that seemed to come out of nowhere. However, it did spark the question I knew would be for my next article series: ‘If our brains can’t feel anything, then how do we feel headaches?’ I mean, when we say ‘oh my head hurts so much’ or ‘my brain is in so much pain’ that doesn’t scientifically make sense. Because, although it may feel like your brain hurts during a migraine or headache, it is actually the tissues surrounding it that are sensitive to pain.
We tend to experience throbbing pain when unpleasant stimuli activate sensory nerve fibres called nociceptors. Although it may feel like a deep pain within your brain, it might surprise you to know that headaches don’t actually originate from the brain itself. These specialised fibres – which are located in the skin, muscles, joints and some organs – transmit pain signals from the periphery to the brain, where the messages of pain are ultimately perceived.
Of course, the brain itself, as we know, doesn’t feel the pain because there are no nociceptors located in the brain tissue itself. This is actually the reason why neurosurgeons can operate on brain tissue without causing a patient any discomfort and in some cases, can even perform surgery while the patient is awake!
Headaches, however, are a different story. Although your brain does not have nociceptors, there are nociceptors in the layers of tissue known as the dura and pia that serve as a protective shield between the brain and the skull. In some cases, chemicals released from blood vessels near the dura and pia can activate nociceptors, resulting in headaches such as migraines. Increased blood flow can also trigger a migraine, which is why migraines are considered vascular headaches.
Migraine headaches are often a persistent throbbing and are accompanied by hypersensitivity to light, sound, and touch. It almost feels like someone, or something is pricking your brain with a sharp pin – we’ve all been there trust me. While we don’t know the exact cause, they’re thought to be the result of abnormal brain activity temporarily affecting nerve signals, chemicals, and blood vessels in the brain. Some people think that migraines are caused by the activation of sensory nerves which release peptides or serotonin, causing inflammation in arteries and the coverings of the brains as well as causing blood vessels to dilate.
The more common tension-type of headache though, do not tend to share migraine features. Although nociceptors are undoubtedly activated in tension-type headaches – partly from the excessive contraction of muscles – other triggers that engage these nociceptors remain unknown. A very important characteristic of these tension-type headaches is that they are increased significantly in stressful situations.
For example, when I was angrily trying to remember a very good article idea and I got rudely interrupted by my sister (I won’t name names but she kind of looked like me) it meant that I lost my train of thoughts and I forgot what I was thinking about and this made me very stressed – momentarily – until I remembered.
Lastly, the second most common headache is the dehydration headache which speaks for itself but then I wondered, how does drinking water help to relieve any sort of headache you may be experiencing? So, here’s why. When you’re dehydrated, your brain can temporarily shrink and pull away from the skull, putting pressure on nerves which causes pain. But the exact reason as to how dehydration causes headaches is unknown as of course, the brain does not have pain receptors. A dehydration headache is possibly triggered by pain receptors in the lining around the brain, called the meninges. When a person is dehydrated, fluid can shift out of the brain, exerting traction on the meninges, which could stimulate the pain receptors.
So, that concludes today’s article, and takeaways are to definitely stay hydrated and remember to have some stress-free time during the day at some point; whether that’s doing some yoga, meditating, going for a walk or reading a book (that’s my fav). See you next week for a new question and a new answer.
