Dehydration & Nerve Pain
by Alison McGinnis, DPT, PT, FAFS
Most of us know that drinking water is vital for our health. Without water, we would die within a few days. And although most of us are not at risk of dying from dehydration, we do forget how our hydration level impacts our bodily functions on a daily basis.
One of the main ways hydration affects our health is it’s impact on our tissues. Connective tissue is made up of three main components: cells, fibers, and an extracellular matrix. The extracellular matrix is a fluid medium that surrounds the cells in all tissues in the body and provides structural support as well as cell-to-cell communication. When we don’t consume enough water, this extracellular matrix diminishes and the space between cells in the body becomes smaller. This reduces the slide and glide between tissues creating stiffness and friction in the body. This increase in friction also leads to a reduction in the threshold to activate pain mechanoreceptors in the tissues. That means it takes less tension/movement to activate the pain awareness pathways to the brain, and you’ll sense discomfort as if you were at end range when you are not. There was also a study done in 2016 by Baer et. al. that showed hypo-hydration (under hydration) increased pain sensitivity in participants. They took the same stimulus (ice bath) and tested individuals when they were hydrated properly and then again when they were hypo-hydrated. Their reported pain level went up when they were dehydrated, even though the temperature of the water stayed the same. This demonstrates that pain levels perceived by the brain are worse when you are dehydrated.
Blood flow through the body is also impacted by prolonged postures or repetitive movements. This can cause regional dehydration where certain areas of the body, like the low back, have less fluid in the tissues leading to increased stiffness and pain. Tissues need blood flow to be healthy, and a lack of movement or too much movement in an area can push fluid out and prevent new blood flow from returning. If soup on a stove stays stagnant, it thickens. What do we do? Stir it. Stagnant movement = stagnant fluid = stagnant health. So keep moving people! Motion is lotion.
So what can you do about it?
- Optimize your hydration. This varies for each individual, but a good rule of thumb is half your body weight in ounces of water (150lbs = 75 ounces). This number increases if you sweat a lot that day or if you consume caffeinated or alcoholic beverages as these are a diuretic. Add 12 ounces of water for every cup of coffee you drink or alcoholic beverage you consume. And according to Dr. Dana Cohen, eating your water is also an effective way to increase your consumption. Think leafy greens or other fruits and vegetables with a high water content, or add chia seeds to your smoothies or breakfast as a way to increase your total water consumption.
- Get moving. This can be accomplished on a local level by using compression (voodoo bands), massage (use your hands or a foam roller), percussion (therapy guns like hypervolt or theragun), or vibration. Or can be done on a global level by moving your body through space (pick your favorite movement practice or just get up and walk around). The bigger the movement/range of motion the greater effect you’ll have on the system. All of these techniques push fluid out of the cells then encourages new blood flow to enter the area. This will reduce the viscosity of the tissues, will decrease the mechanoreceptor activation, and will reduce the pain signals being sent to the brain.
- Check out our videos on Instagram for how to use these different tools or take one of our movement classes offered at the Foundry to jumpstart your practice.
The next time you’re feeling pain, especially chronic pain, track your hydration levels. Drinking water is probably a missing piece in your recovery process and may be a big reason your progress may have stalled or isn’t going as fast as you might like. And it’s super easy to fix!