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Medically reviewed by
Dr Meena Zareie (GMC) — Updated on December 29, 2025
Dr Meena Zareie (GMC) — Updated on December 29, 2025
Healthy hair is smooth, soft, and shiny, regardless of its natural texture. However, it’s not always easy to keep it this way. As a result, many of us, particularly women, end up with dry and damaged hair that looks and feels less than its best.
Lots of factors can cause your hair to become frizzy and fractured, from environmental issues to styling treatments. These elements impact the layers of your hair in different ways, causing them to become fragile, cracked, and rough. Often, damaged hair results from cracks in the hair cuticle, which exposes the hair cortex:
In this article, you’ll learn everything you need to know about damaged hair, including:
- What causes damaged hair
- How to repair hair damage
- Ways to prevent damage to hair
- What you can do to keep your hair healthy.
What is damaged hair and what does it look like?
Damaged hair happens when the hair cuticle lifts and opens, exposing the layers beneath.
The hair cuticle consists of overlapping scale structures. These scales can become dislodged over time as a result of harmful practices and pollutants.
As these scales move, the cuticle becomes prone to splitting, cracking, and breaking, making your hair look dry, brittle, and dull.
Damaged hair can manifest in lots of different ways, including:
- Split ends
- Dry, frizzy texture
- Mid-shaft hair breakage known as trichorrhexis nodosa
If these problems impact your hair as a whole, your hair will lack shine and the ends of your hair will start to fray and thin.
If left untreated, damaged hair can become tangled and even matted. At this point, some people refer to it as dead hair that can only be repaired by cutting it off.
If you think your hair is becoming damaged, it’s important to recognise what’s causing the problem and treat your hair as soon as you can. This will help protect hair against further damage and help keep your hair looking its best.
Damaged hair causes and treatment at a glance
| Cause of damaged hair | Treatment for damaged hair |
Colouring and bleaching:
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Chemical treatments:
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Heat styling:
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Excessive grooming:
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Tight hairstyles:
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Poor diet:
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Pollution and environmental factors:
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How does hair get damaged?
Lots of factors can contribute to damaged hair, from common causes like heat styling and chemical treatments to lesser-known issues like your diet and exposure to pollutants.
Here are the 7 major causes of hair damage, plus 22 effective ways to prevent, repair, and treat damaged hair.
Damage from colouring or bleaching
Bleach strips your hair of its natural pigment by oxidising melanin in the hair cortex [2]. Dark hair contains more melanin than lighter shades, so bleach must be applied for longer to remove the pigment from the hair.
Oxidation destroys the bonds within the hair’s keratin, a protein that makes up 65-95% of your hair shaft [3]. This can make the hair cuticle more porous and prone to damage.
Mixing hair bleach with chemical treatments can cause more significant damage, as well as cosmetic problems. This image shows the results of applying bleach after a chemical treatment, leading to severe hair breakage and colour issues:
4 ways to repair/prevent damaged hair from colouring and bleaching
- Avoid bleach if your hair is already damaged, especially if you’ve used lots of treatments and dyes before. Your stylist should be open with you about whether bleach is appropriate for your hair.
- Always do a strand test before using hair dye or bleach, even if you’ve used the product before.
- Use the right shampoo and conditioner to maintain your colour, so you need less frequent top-ups. Toners are generally safe for hair, and can also help with colour maintenance.
- Keep track of which dyes, bleaches, and treatments you use. This includes keratin for hair treatments. If possible, find out exactly what products your stylist is using. That way you have an accurate hair history if you change your style in the future.
- Embrace your natural colour and grey hair! Stop playing catch-ups with colour treatments and start to make a transition to your natural hair colour. Check out our expert tips on transitioning to grey with highlights.
Damage from chemical treatments
Relaxers, perms, and other treatments chemically alter the structure of your hair, changing the texture without the need for daily styling:
- Relaxers — A strong alkali solution, also known as lye or sodium hydroxide, is applied to the hair, which softens tight curls and kinks.
- Hair rebonding — A perming solution is applied to break the hair’s natural bonds. These bonds are then restructured using a hair straightener, creating long-lasting straight hair.
- Perms — A perm is rebonding in reverse. Instead of restructuring the bonds with a hair straightener, the bonds are set into a curled pattern.
Chemically altering the structure of your hair often leads to damage. One study found that 96% of people using chemical hair relaxers reported adverse effects, the most common being frizziness, dandruff, and hair loss [4].
Perms damage your hair by exposing the hair cortex, which happens when the cuticle lifts or cracks excessively [5]. It can also cause bubbles to develop in wet hair following heat exposure [6].
2 ways to repair/prevent damaged hair from chemical treatments
- After your first chemical treatment, future processing should only be applied to the hair roots to prevent damage through the lengths of your hair strands [1].
- Avoid damage caused by chemical runoff by coating previously treated hair an effective carrier oil. Both coconut oil for hair and castor oil for hair are good options for this.
Damage from heat styling
Heat can lead to hair loss if it’s overused, so subject your hair to minimal heat styling. This includes:
- Blow drying
- Hair straighteners/flat irons
- Curling tongs
Blow drying your hair at temperatures from 47°C can cause your cuticle to lift and crack, resulting in rough, broken hair shafts [7-8]. So curling tongs and straighteners that apply heat of up to 200°C directly to your hair can also cause significant damage.
Natural remedies like apple cider vinegar for hair may help keep your hair cuticle intact. But this hasn’t been proven yet, so it’s best to stick with tried and tested methods for protecting your hair from heat styling. See the most effective treatments for hair that feels like straw.
4 ways to repair/prevent damaged hair from heat styling
- Limit your use of heat styling tools to once or twice a week.
- Use a heat protection spray to create a barrier between your hair shaft and the heat, keeping moisture in and minimising damage.
- Reduce the temperature of your tools to the lowest setting.
- Move tools along the hair shaft to avoid applying too much heat to one section of your hair.
Damage from excessive brushing and shampooing
Even everyday grooming activities like brushing and washing your hair can cause damage. This is a major cause of damage in virgin hair (that is, natural hair that hasn’t undergone any chemical treatments, dye, or bleach) and can lead to [9].
Excessive brushing can lead to trichorrhexis nodosa, which is characterised by shafts of different lengths, dryness, and multiple whitish-grey breakage points.
Grooming practices that can damage your hair include:
- Excessive brushing — Brushing removes tangles and knots, but brushing too much can cause abrasion that damages the hair.
- Hair washing — Applying shampoo too vigorously or too often can result in breakage along the hair shaft. See the best shampoos for dry hair.
- Vigorous towel-drying — Rubbing your hair with a towel causes friction that can damage the hair cuticle.
Eventually, these practices will lead to the formation of split ends, a type of irreparable trichoclasis [9]. Lots of split ends usually lead to the appearance of thinning hair in women, who tend to have longer hair. Find out more about split ends vs healthy hair.
3 ways to repair/prevent damaged hair from hair grooming
- Brush or comb your hair gently, being careful not to yank the brush through any knots or tangles. Start at the ends and gradually tackle the lengths of the hair. Try to use a wide tooth comb when detangling.
- Don’t rub your hair when towel-drying. Allow the fabric to absorb the moisture. Then air dry or use a blow dryer on a low heat setting.
- Trim your hair regularly to get rid of split ends.
Damage from tight hairstyles
While styling your hair in an updo or braids from time to time isn’t a problem, repeatedly wearing your hair in tight styles can lead to breakage and frizz. If left untreated, it can even cause traction alopecia, a type of alopecia triggered by excessive tension on the hair follicle [10].
Styles that often lead to breakage include:
- Tight ponytails and buns
- Hair extensions
- Braids
- Dreadlocks
- Weaves and wigs
These styles add weight and tension to the hair, which can result in significant breakage [11].
Many of these styles are popular protective styles for afro hair. So it’s not always easy to simply avoid wearing your hair in these styles. Instead, apply good haircare practices to keep your hair in good condition.
4 ways to repair/prevent damaged hair from tight hairstyles
- Make sure your style isn’t so tight that it tugs on your follicles. Ask your stylist to make your braids or locs looser if necessary.
- Don’t incorporate baby hairs or edges into your style, as these are particularly fragile and prone to breakage. Wear your hair in safe hair loss hairstyles for crown thinning.
- Condition and oil your hair regularly using products that are suitable for your hair type and texture.
- If possible, minimise how often you wear your hair in protective hairstyles. Try not to keep your hair in the same style longer than four weeks [10].
- Find out what to do about frizzy broken hair on top of your head.
Damage or hair loss from vitamin or nutrient deficiencies
What you eat can have a serious impact on both your hair and scalp health. So it’s important to incorporate lots of nutritious hair growth foods into your diet.
Some vitamin deficiencies can even lead to hair loss [12]. That’s why you need to get plenty of the following nutrients in your diet:
- Iron for hair
- Vitamin C for hair
- Vitamin E for hair
- Biotin for hair and other B vitamins
- Vitamin D for hair
- Zinc for hair
- Other essential hair health vitamins
Applying vitamin formulas directly to your hair is unlikely to improve or repair hair damage. Instead, you’ll need to incorporate lots of nutrient-rich foods into your diet to maintain your hair health.
How to repair/prevent damaged hair from nutrient deficiencies
- For healthier hair, make sure you’re eating a balanced diet that includes plenty of foods that nourish and strengthen your hair.
Damage from pollution and the environment
Exposure to environmental factors like chlorine, ultraviolet rays, and even air pollution can also damage your hair [13-14]. These can be even more harmful to people with bleached, dyed, or grey hair.
Chlorine can change the colour of virgin hair. When combined with UV exposure, it can also compromise your hair proteins [15]. Saltwater can also damage your hair.
4 ways to repair/prevent environmental hair damage
- Wear a swimming cap to protect your hair, especially if you’re swimming outdoors in a sunny place.
- Wearing a hat may help protect your hair from UV rays and air pollution (don’t worry, wearing a hat won’t cause hair loss).
- Take extra care in the sun, sea, and swimming pool if your hair is dyed or bleached.
- If you live in a hot or humid climate, condition your hair regularly to keep it moisturised and healthy.
Is there a way to repair damaged hair?
It’s not usually possible to repair damaged hair once the cuticle has lifted or cracked. Damaged cuticles leave your hair brittle and prone to split ends, which can lead to additional hair shaft damage and even thinning. That’s why it’s important to get your hair cut or trimmed regularly to remove problematic ends.
You may be able to smooth and soften your brittle hair with the right products:
- A leave-in conditioner or hair mask can help to moisturise your hair, reducing dryness and tangling (especially if infused with a humectant like hyaluronic acid for hair).
- Coconut oil can help protect your hair from the drying effects of shampoo [17].
- Anti-dandruff and anti-fungal shampoos can help tackle dandruff, seborrheic dermatitis, and fungal hair conditions [18].
What should I do to keep my hair healthy?
Hair damage prevention is the best way to keep your hair looking and feeling great. Here are ten ways to prevent damaged hair:
- Don’t wash your hair more than you need to. Washing your hair every day can make it feel dry. Oily hair may need more regular washes, while people with dry hair can often limit hair washing to two or three times a week.
- If you’re considering a hair treatment, discuss a plan with your hair stylist. Plan for top-up treatments you might need, and discuss how you can minimise damage to your hair when it’s processed. This may involve treating each section of the hair (e.g. roots, lengths, ends) differently.
- Use a coconut oil pre-wash. Coconut oil is an effective dry hair treatment. Applying coconut oil to your hair for 20-30 minutes before you wash it can prevent water from penetrating your hair, causing cortex expansion and cuticle cracking.
- Use heat styling tools on their lowest setting. Lower temperatures tend to cause less damage than ultra-hot tools.
- Blowdry your hair in the direction of growth (or use a diffuser). Blow drying down the hair shaft can help the cuticle lie flat, rather than encouraging it to lift. For curly hair, a diffuser can help prevent damage while blow drying.
- Wear a hat or headscarf in the sun. As well as keeping you cool, covering your hair in the sun can reduce exposure to harmful UV rays.
- Change your protective style regularly. If you have an Afro hair type and choose to wear your hair in a protective style, try to switch your style at least once a month to reduce tension in your curls and prevent undue stress on your follicles.
- Keep track of your hair treatments. Knowing which chemicals and products have been used on your hair can help your stylist decide which treatments are safe, preventing problems from arising on your next trip to the salon.
- Use heat protectant spray. This is essential if you regularly use heat styling tools on your hair.
- Learn about your hair type and texture. Different hair types need unique care, so make sure you’re using products and practices that are best for your hair.
If you are worried about the health of your hair and would like a professional opinion regarding damage or even hair loss, contact one of our hair loss specialists today. We can help assess your hair loss and create a treatment plan specialised just for you.
Contact us today for a free no-pressure consultation at Wimpole Clinic, winner of the 2023 Hair Transplant Clinic of the Year award (three years running).
Sources:
- Healthy Hair: What Is it?
- Hair care products: waving, straightening, conditioning, and coloring
- Hair Keratin | Science Direct
- Chemical Hair Relaxers Have Adverse Effects a Myth or Reality
- The Change of Hair Surface According to Perm Treatment Method
- Blowing Bubbles: Dermoscopy of Bubble Hair
- Hair Shaft Damage from Heat and Drying Time of Hair Dryer
- The cracking of human hair cuticles by cyclical thermal stresses
- A study of damaged hair
- The art of prevention: It’s too tight—Loosen up and let your hair down
- All hairstyles are not created equal: Scalp-pulling and hair loss
- The Role of Vitamins and Minerals in Hair Loss: A Review
- Human pollution exposure correlates with accelerated ultrastructural degradation of hair fibers
- Using wearable devices for assessing the impacts of hair exposome in Brazil
- Hair color damages caused by exposure to chlorinated water in the presence of ultraviolet radiation
- Understanding Hair Loss due to Air Pollution and the Approach to Management
- Effect of coconut oil on prevention of hair damage.
- The antifungal action of dandruff shampoos
Medically reviewed by Dr Meena Zareie (GMC)
— Updated on December 29, 2025
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
Talk to a specialist ☎ 020 7935 1861.
Talk to a specialist ☎ 020 7935 1861.
Medically reviewed by
Dr Meena Zareie (GMC) — Updated on December 29, 2025
Dr Meena Zareie (GMC) — Updated on December 29, 2025
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