Dry, brittle or unmanageable hair can be caused by a range of factors, from environmental conditions and styling practices to water quality and underlying health issues. Understanding these root causes is essential to identifying the most effective solutions.
In this article, we’ll explore the most common causes of hair dryness, including often-overlooked contributors like hard or chlorinated water. You’ll also learn how improving your water quality can support healthier hair.
What causes dry hair?
Dry hair can occur naturally for those with certain hair types or who don’t produce enough oil to keep the hair adequately hydrated. However, it can also result from heat styling, harsh weather, hard water, overwashing and chemical treatments. Each of these factors can strip moisture, weaken the hair cuticle and lead to symptoms like frizz, itchiness or breakage.
5 common causes of dry hair
Below, we break down five of the most common causes of dry hair — and how to address them:
1. Washing your hair too often
Washing your hair too frequently can strip away the natural oils that help protect and hydrate each strand. While shampoo is important for removing buildup and maintaining scalp health, overuse may contribute to dryness, irritation and even breakage — especially for individuals with dry or textured hair.
There’s no universal rule for how often to wash your hair. The right frequency depends on a combination of factors, including hair type and oil production:
- Finer or oil-prone hair may need to be washed every other day.
- Medium to coarse hair typically benefits from washing every few days.
- Thick, curly or chemically treated hair may only require washing once a week or less.
If you think you may be overwashing, try gradually extending the time between washes to see how your hair responds. In the meantime, focus shampoo application on the scalp and reserve conditioner for the ends to help maintain moisture balance and reduce breakage.
2. Heat styling tools
Dry hair could also be due to your heat styling tool. Curlers, straighteners and high-heat blow dryers can dry out your hair and damage the cuticles.
To help protect your hair from heat damage, allow your hair to air dry. If you need to use styling tools, be sure to blow-dry your hair (ideally on a cool setting) before applying heat.
You can also apply a heat-protectant spray to dried hair for extra safety. These sprays work to provide thermal protection to your hair by building a layer on the hair’s cuticle. This may help prevent the breakdown of the hair’s natural proteins, which could help your hair feel strong and smooth. For the best results, cut heat styling tools out entirely.
3. Harsh products and chemical treatments
Harsh, oil-stripping treatments like perms, dyes and relaxers can remove the natural oils from hair. Hair dyes and bleaches are notorious for their drying effects. Most commercial dyes use peroxide to desaturate your hair’s natural color. This ingredient causes dyed hair to become dry and straw-like.
Permanent treatments combined with bleaches and dyes can lead to more extreme cases of hair damage, including breakage at the scalp. To keep your hair feeling soft and shiny, avoid chemical treatments when possible.
4. Weather and environmental conditions
Dry air lifts the hair cuticle, which releases moisture and causes breakage and frizz. Those in warm climates are also at risk of too much UV exposure from the sun. This can also cause hair to become dry and brittle.
Take care of your hair by hydrating it with oils and products that restore moisture at the root. You can also use hats or sweatshirt hoods to protect your hair from the elements.
5. Hair type
Some curly hair and textured hair types are naturally more prone to dryness. This is because the bends and twists in the strand make it harder for the scalp’s natural oils to travel evenly from root to tip. Without that natural lubrication, ends can dry out faster, leading to frizz, split ends and breakage.
While hair care products like leave-in conditioners and hair oil can provide temporary relief, they don’t always address the underlying factors. If you’re noticing persistent dry hair symptoms despite using moisturizing shampoo or conditioner, it may be worth looking beyond styling and product use.
Water quality: The overlooked factor in dry hair
When people think about dry hair causes, they often focus on styling tools or harsh products. But what’s flowing from your tap can play just as big a role. Two of the most overlooked factors are hard water and chlorine.
Hard water
Hard water has high concentrations of minerals like calcium and magnesium, which build up on your hair and skin. This can create a film on the surface of the skin that prevents natural oils from reaching the skin barrier which can lead to dryness and irritation. This buildup can also leave hair dry and stiff, and make it harder for shampoos and conditioners to lather and rinse properly.
Hard water can be difficult to spot. Because you can’t see or smell it, you may not realize you have high levels of water hardness until you notice the impact on your hair, skin or around your home. The best way to catch and address hard water issues is to have a professional water test and consultation. You’ll learn all about your home’s water quality, including hardness levels, pH and other potential water quality concerns. You’ll also get recommendations on how to treat it.
Chlorine
Chlorine is widely used to disinfect pools and municipal water supplies. While the U.S. Environmental Protection Agency and Health Canada regulate allowable chlorine levels in municipal drinking water, chlorine can strip away the natural oils that protect and hydrate your hair.
Frequent swimming in chlorinated water may leave it feeling dry, brittle or rough to the touch. If you have city water, the chlorine used in the treatment process could also have a negative ongoing effect on your hair.
To help protect your hair from chlorine-related dryness at the pool:
- Wet your hair with fresh water before entering the pool to reduce chlorine absorption.
- Apply a leave-in conditioner or protective oil to lock in moisture.
- Wear a swim cap to minimize direct exposure.
- Rinse your hair immediately after swimming to help dilute any lingering chlorine.
- Use a hydrating shampoo and conditioner to help restore softness and strength.
For the home, a whole home water filtration system is one of the most effective solutions because it treats chlorine at the source. Pairing better water with moisturizing hair products can further support healthy-looking hair and reduce the signs of chlorine-related dryness. If you have hard water and high chlorine levels, you can also look for a water softener designed to address both issues.
It’s important to note that neither hard water nor chlorine have been proven to directly cause hair conditions like hair loss. However, both can exacerbate dryness and make hair look or feel less healthy. Addressing these overlooked water quality factors can help support healthier-feeling hair and reduce reliance on heavy styling or conditioning treatments.
How does hair structure work?
Understanding hair structure can help explain why issues like dryness or breakage happen, and how to address them.
Each strand of hair has a visible shaft made up of three main layers:
- Cuticle: The outermost layer acts as a protective shield. It’s sensitive to changes in the environment and water quality including factors like water chemistry and pH.
- Cortex: This is the inner core of coiled proteins that gives hair its strength, shape and elasticity. When the cuticle is worn down and the cortex becomes exposed, split ends and rough texture can occur.
- Medulla: This is a soft, spongy center found in thicker hair types. Fine or thin hair often lacks this layer altogether.
Beneath the skin, the root anchors the hair in place and is surrounded by a follicle — tissue connected to sebaceous glands that produce oil. These natural oils help keep your hair moisturized. If the glands don’t produce enough oil, or if buildup from shampoo or hard water interferes, dryness can start at the follicle.
At the base of each strand is the bulb, where new cells form and harden before being pushed upward through the skin. Hair typically grows about 1 centimeter per month. The shape and growth pattern of your hair — whether it’s straight, wavy or curly — can also affect how easily moisture travels down each strand, which is why some hair types are more prone to dryness than others.
Why better water equals better hair
Every time you wash your hair, the water you use interacts with your hair shaft, scalp and hair follicles. If that water contains excess minerals, chlorine or other undesirable components, these substances can build up and interfere with moisturizing ingredients in your shampoo or conditioner, dry out your scalp and contribute to brittle or damaged hair over time. That’s why improving water quality is an essential — and often overlooked — step toward achieving smoother, shinier and healthier-looking hair.
Here are three ways to support better hair through better water:
1. Water softening
A water softener removes excess minerals from your water supply, helping you prevent hair damage at the source. Soft water rinses cleaner, supports more effective lathering and helps reduce reliance on additional hair treatments or styling products.
Explore water softening solutions.
2. Whole home filtration
Whole home water filtration can address specific issues, such as chlorine, iron, hydrogen sulfide and more. When you choose a whole home system, you get improved water quality at every tap.
3. Under sink filtration
While water softeners and whole home filtration improve specific water issues throughout your home, under sink filtration targets the water you drink with comprehensive filtration. These systems can use filtration technologies like reverse osmosis to address a wide range of impurities that may be present in tap water, helping you stay hydrated to support hair wellness from the inside out.
Frequently asked questions about dry hair
Why doesn’t hair hold moisture?
Porosity plays a large role in how well your hair retains moisture. If the cells in the cuticle are packed tightly, there’s no room for water or healthy oils to get in, meaning low porosity can sometimes lead to hair dryness.
To test your hair’s porosity, remove one freshly cleaned strand and put it in a glass of water. If it floats, it likely has low porosity; if it stays near the middle or sinks, it probably has higher porosity.
How do you know you have dry hair?
Dry hair isn’t always immediately visible. Often, the first sign is how your hair feels. It may start to feel rougher, lose its shine or become more difficult to style.
As dryness progresses, you might notice additional symptoms like frizz, brittle strands or a dry, irritated scalp. These changes can develop gradually — and in many cases, are made worse by factors like hard water, chemical treatments or overwashing.
What are the downsides of dry hair?
Dry hair often leads to increased product use — conditioners, masks, serums, etc. — all trying to restore what’s missing. If you don’t address the underlying cause, those efforts may fall short. Over time, the feel or look of your natural hair can change, simply because dryness has disrupted its balance.
Can soft water help with dry hair?
Yes — a water softener can make a noticeable difference for many households dealing with dry hair. Softeners work by reducing excess hardness minerals, specifically calcium and magnesium. The result is soft water that interacts more gently with your hair and skin.
Step up your hair care routine with water solutions
If your hair feels dry, brittle or hard to manage, the solution may not be another hair care product — it might be your water.
While deep conditioners, hair masks and smoothing treatments can temporarily improve the appearance of dry or damaged hair, they often don’t address the underlying issue. For instance, chlorine or mineral buildup from hard water can strip moisture, irritate the scalp and weaken the hair shaft, especially in individuals with dry scalp or textured hair types.
Improving your water quality can help restore your hair’s natural moisture balance, reduce reliance on heavy hair products and support healthier, stronger strands over time.
Culligan water solutions for dry hair
Culligan offers several solutions designed to make your water gentler on your hair and skin:
- Aquasential® Smart High Efficiency Water Softener reduces hardness minerals, with Aqua-Sensor® technology and Dial-a-Softness® control for customized softness.
- Aquasential® Smart High Efficiency Municipal Water Softener treats both hardness and chlorine to help protect hair and skin from dryness.
- Aquasential® Smart Whole Home Water Filtration System targets chlorine at the source, delivering better water for every shower, tap and household task.
Schedule your free, in-home water test and consultation with your local Culligan water expert today to get expert recommendations tailored to your hair and home.
*Contaminants may not be present in your water.