You eat well, exercise regularly, and feel like you have a good handle on your health. Yet it often feels like your stress system is activated, even when there’s no reasonable cause. Life doesn’t feel particularly stressful, so why are you so low on energy and find it hard to unwind?
It can be easy to start thinking about sleep, hormones, or blood sugar levels. But sometimes it’s about something much less noticed when it comes to the body’s stress response – namely sodium.
Most people associate sodium with salt, but in the body, sodium is much more than that. You may already know that it helps regulate the body’s fluid balance and blood volume, among other things. But did you know it’s also involved in the nervous system’s signaling?
When the body senses that important resources like sodium or fluids are becoming scarce, several of our most vital survival systems are activated.
Sodium is an important signal to the body
Sodium is one of the body’s most important electrolytes, regulating how fluids are distributed between the blood, tissues, and cells. So if you consume too little sodium, or if losses exceed intake over a longer period, the body will need to compensate.
This activates, among other things, the RAAS system—the renin-angiotensin-aldosterone system.
Simply put, it functions as the body’s way of detecting when the supply of fluids and sodium starts to decrease. When this happens, the body tries to retain more fluid, preserve sodium, and maintain blood pressure.
And here the connection to the body’s stress response becomes clearer.
Research shows that low sodium intake leads to increased levels of renin and aldosterone, two hormones that help the body retain sodium and fluids. Meta-analyses have also shown that levels of noradrenaline can increase. Noradrenaline is one of the body’s most important stress-related signaling substances.
In other words, the body reacts when sodium availability decreases. It not only tries to save sodium and fluids but also activates several hormonal systems that help it manage the situation and secure access to vital substances and resources.
Where does cortisol come into the picture?
Cortisol is a hormone that helps the body mobilize resources when you need to adapt to stress. And although research does not show that low sodium levels automatically lead to high cortisol levels in everyone, there are biological mechanisms linking the two.
When the body needs to work harder to maintain fluid balance and blood pressure, this can contribute to increased physiological stress activation. And this is where the connection to cortisol becomes relevant. The body doesn’t always distinguish between different types of stress; it simply responds to the signals it receives.
When might you need to consume more sodium?
For most people eating a varied diet, sodium deficiency is rare. But certain situations can increase the need for or losses of sodium. For example:
- intense or prolonged exercise
- excessive sweating
- hot climate
- fasting
- large amounts of fluids during the day
- alcohol
- stomach illness with diarrhea or vomiting
In these situations, it can be wise to pay extra attention to your body’s signals and ensure both fluids and electrolytes are replenished.
There is often more behind the symptoms
Sodium—and the availability or deficiency of it—shows how closely interconnected the body’s various systems are.
- When sodium levels change, fluid balance is affected.
- When fluid balance changes, the signals that help the body determine whether vital resources are available or becoming scarce are also affected.
- And when those signals change, hormones are affected as well.
This is also why it can sometimes be confusing to experience several individual symptoms. Fatigue, stress activation, or poorer recovery can have many causes. But sometimes the chain starts with something as fundamental as the body’s access to fluids and minerals.
