Fluid retention is one of those things people notice quickly.
It shows up as puffiness in the face, swelling in the fingers, or that heavy feeling in the legs and ankles. It can come and go, or linger longer than expected.
But it’s rarely random.
Fluid balance in the body is influenced by multiple systems working together, including hormones, circulation, and how your kidneys process fluids. When something is slightly off, the body can start holding onto water instead of releasing it properly.
“Fluid retention is usually a sign that something isn’t quite balanced,” says Madeline Calfas, registered nurse and nutritionist. “It’s not just about water itself, it’s about how the body is regulating it.”
Here are some of the more common factors that can make a difference.
It often starts with sodium
One of the biggest contributors is sodium intake.
Highly processed foods, takeaway meals, and packaged snacks tend to contain more salt than people realise, which can shift how the body holds onto fluid.
“When sodium levels are high, the body naturally holds onto more water,” Madeline explains. “It’s part of how it maintains balance.”
This doesn’t mean cutting everything out, but being more aware of where sodium is coming from can help reduce that constant feeling of puffiness.
Potassium plays a bigger role than people expect
It’s not just about reducing salt, it’s also about balancing it.
Potassium helps regulate fluid levels and supports the body in releasing excess water.
“In most cases, the ratio between sodium and potassium is off,” says Madeline. “People tend to consume more sodium and not enough potassium.”
Adding foods like leafy greens, avocado, and vegetables can help support that balance more naturally.
Drinking more water can actually help
It sounds counterintuitive, but not drinking enough water can make fluid retention worse.
When the body feels like it’s not getting enough hydration, it tends to hold onto what it has.
“The body is very good at adapting,” Madeline says. “If it senses a shortage, it will retain fluid as a protective mechanism.”
Staying consistently hydrated helps signal that it’s safe to release excess fluid.
Stress can show up physically
Fluid retention isn’t always just about diet.
Stress plays a role too.
When cortisol levels are consistently elevated, it can influence how the body holds onto sodium and water, which can contribute to swelling.
“Stress affects more than people realise,” says Madeline. “It changes how the body functions on multiple levels, including fluid regulation.”
This includes not just emotional stress, but also physical stress like lack of sleep, overtraining, or restrictive eating.
Food sensitivities can contribute
For some people, ongoing fluid retention can be linked to inflammation.
This can happen when the body is reacting to certain foods regularly, even if the reaction isn’t immediately obvious.
“When there’s underlying inflammation, the body can start holding fluid as part of that response,” Madeline explains.
Common triggers can include dairy, gluten, or other individual sensitivities, but it varies from person to person.
Magnesium is often overlooked
Magnesium plays a role in multiple processes in the body, including muscle function and fluid balance.
Low levels can contribute to water retention, particularly for women around hormonal changes.
“It supports how the body manages electrolytes,” says Madeline. “And that directly impacts fluid balance.”
Including magnesium-rich foods, or addressing low levels where needed, can help support this.
What actually makes a difference
Fluid retention isn’t always caused by one single thing.
It’s usually a combination of factors, which is why quick fixes don’t always work long term.
Looking at overall habits, hydration, diet, stress, and consistency tends to be far more effective than trying to target just one area.
“If it’s ongoing or not improving, it’s worth looking a bit deeper,” Madeline says. “Sometimes there can be underlying reasons that need to be addressed properly.”
Because while occasional fluid retention is common, persistent swelling is something that shouldn’t be ignored.
