Can hard water cause eczema? What the science says

If you’ve got sensitive skin or eczema, you’re probably already careful about the soaps and creams you use. But have you ever thought about the water coming out of your tap?

Hard water might not be dangerous to drink (in fact, it has some health benefits), but it can definitely have an impact on your skin — especially if it’s already on the reactive side.

So what does the science actually say? Can hard water cause eczema, or just make it worse? And what can you realistically do about it? Let’s take a look.

What is hard water, and why does it matter for your skin?

Hard water is full of minerals — mainly calcium and magnesium — which it picks up as it travels through chalky or limestone-rich ground. Around 60% of the UK has hard or very hard water, especially in the South East, South West, and parts of the Midlands.

These minerals might sound harmless (and they are when you drink them), but they don’t always play nicely with your skin. They react with soap to form a film that can clog pores, make cleansers harder to rinse off, and leave residue on your skin. Over time, this can weaken your skin barrier and dry your skin out — not ideal if you’ve got eczema or any kind of sensitivity.

What the research says

Several UK studies suggest that hard water doesn’t just make eczema worse — it might even increase the chances of developing it in the first place.

A 2020 study published in The Journal of Allergy and Clinical Immunology found that washing with hard water damaged the skin barrier and increased irritation, particularly in people with a genetic risk of eczema.

Another study from the University of Sheffield and King’s College London found that hard water raised the skin’s pH and reduced natural moisturising factors — two things that can contribute to dryness and inflammation.

Study overview

And in a large UK-based trial by the same teams, babies living in hard water areas were found to be 87% more likely to develop eczema. While that stat’s about infants, it reinforces how harsh mineral-heavy water can be on delicate or compromised skin.

As Dr Derrick Phillips, consultant dermatologist and spokesperson for the British Skin Foundation, puts it:

“The minerals in hard water can disrupt the skin’s natural barrier, making it more prone to dryness and flare-ups — especially in people with eczema.”

So if your skin feels tight, itchy or more irritated after a shower, your water might be partly to blame.

How hard water might be making your eczema worse

If you’ve never thought about how water affects your eczema, you’re not alone. But here’s how it might be playing a role:

Soap scum residue

Hard water leaves a film on your skin, which can trap allergens or bacteria and trigger flare-ups.

Higher skin pH

Hard water can make your skin more alkaline, which weakens your natural barrier and makes it harder to retain moisture.

Cleansers that won’t rinse off

Soaps and body washes may react with minerals in the water, making them harder to rinse and more likely to irritate your skin.

Increased dryness

If your skin’s barrier is already struggling, hard water can push it over the edge — leading to more flaking, itching, and inflammation.

What you can do about it

If you think hard water could be affecting your skin, here are a few ways to manage it — no major plumbing required:

Use a shower filter

Shower filters like Hello Klean can help reduce chlorine, heavy metals, and some mineral residues. While they don’t fully soften water, many people with eczema find their skin feels calmer and less dry after switching.

Switch to low-pH cleansers

Opt for soap-free, fragrance-free washes designed for sensitive skin. They’re less reactive with minerals and gentler on the skin.

Moisturise right after washing

Apply an emollient straight after your shower or bath, while your skin is still damp. It helps lock in hydration before it evaporates.

Test your water

Not sure how hard your water is? Most UK water suppliers list hardness levels by postcode, or you can pick up an at-home test kit online.

Consider a full-home softener

If you’re dealing with persistent eczema and live in a very hard water area, a softener might be worth considering. It’s a bigger investment, but it removes the minerals that contribute to dryness and scale build-up — both in your home and on your skin.

Why it’s worth paying attention to

Managing eczema can feel like an endless cycle of trial and error. If you’ve already tried switching skincare products and nothing seems to work, it might be time to think about what’s coming out of your taps. Hard water isn’t always the root cause, but for people with eczema or sensitive skin, it can definitely make things worse.

The research suggests it’s not all in your head — and even small changes like switching your cleanser or adding a shower filter could help soothe your skin and calm things down.

✨ Limescale lowdown ✨

• Hard water can leave mineral residue on your skin, drying it out and triggering flare-ups.

• UK studies link hard water to increased eczema risk and irritation.

• Shower filters and gentle, low-pH cleansers can help.

• In very hard water areas, a softener might be worth it.