You’ve loved your hair.
It’s always been straight and flowy.
But recently, you’ve noticed that you’re developing waves, curls even.
You are curious and at the same time surprised.
Why is your straight hair turning curly?
There are multiple reasons why your straight hair could be turning curly. It could be genetic (one of your parents has curly hair), hormonal (PCOS or thyroid disorders), or due to other factors like chemotherapy, stress, or diet changes.
I’ll talk more about these in this post.
It could be 1 or several reasons – so I’ll leave it up to you to decide what’s happening.
I’ll also talk about how you can stop your hair from turning curly.
Let’s dive in!
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1. Genetics is playing a role
Genetics will play a huge role in the texture of our hair – and sometimes your texture will change over time.
Now, you need to understand that hair texture is largely determined by the shape of the hair follicle:
- Straight hair is usually associated with a circular-shaped hair follicle
- Curly hair has an oval-shaped hair follicle
When the hair follicle is oval, it causes the hair to grow in a curved shape – this results in curly/coily hair.
I’m going to attach a diagram I drew myself below (yes, I draw) to help you understand this better:
African hair follicles are more oval than Asian or Caucasian hair follicles generally. This is why they usually have curly or coily hair.
Now, the genes you inherit from both of your parents are going to influence the shape of the hair follicle.
Let’s say you inherit the genes for straight hair from 1 parent – and the genes for curly hair from the other, then even if your hair is straight as a child, it is possible for the hair texture to change from straight to curly over time.
Sometimes, certain genes can also be activated or deactivated due to environmental facts, like hormonal levels, lifestyle changes, or even exposure to certain chemicals and toxins – I’ll talk more about this in a bit.
Genetics is only 1 of the many factors that can contribute to your straight hair becoming curly.
2. You’re experiencing hormonal changes
Hormones are chemical messengers that play a very important role in our bodies by regulating various functions including hair growth and development.
So, hormonal changes can affect the shape of the hair follicles which will influence the level of curliness or straightness of your hair.
My mum told me her hair became more wavy during pregnancy. And I used to find it odd – not anymore!
Pregnancy and menopause can cause a lot of hormonal changes and this does affect hair texture.
During pregnancy, increased levels of estrogen can cause hair to become more thick and shiny. Obviously, this does change after pregnancy because hormone levels return to normal.
But in the cases of PCOS (polycystic ovary syndrome) which actually affects a lot of women, can lead to a lot of hormonal imbalance.
Some women experience increased levels of androgen which can cause hair to become curlier.
Thyroid disorders (my friend has Hahimoto’s Disease and this has led to hair thinning) can also lead to a change in hair texture because thyroid hormones affect hair growth and development too!
Also, as we age, changes in hormone levels will lead to changes in hair texture.
As women, our estrogen levels decline during menopause and this can cause hair to become thinner, drier, and more prone to breakage.
If you feel age might be the reason why your hair is becoming curly, then speak to a healthcare provider to determine whether there is an underlying hormonal imbalance or disorder that needs addressing.
3. Excessive heat from styling tools may be causing your hair to turn curly
For many years, I used heating tools like there were no repercussions – unfortunately, there are.
When you use a heating tool like a curling iron or hot rollers, you’re applying heat directly to your hair strands.
This head can break down the hydrogen bonds that hold your hair in a natural, straight shape.
This means your hair becomes more malleable and easier to style.
But over time, repeatedly using heating tools on your hair can actually cause those hydrogen bonds to reform in a new, curly shape and it can result in your hair becoming permanently curly.
Now, before you toss out your heating tools, please note that this process does take time and isn’t foolproof.
Not everybody’s hair will turn curly from heat-styling and some people’s hair may only develop a slight wave or curl pattern.
But using heating tools regularly will cause damage, dryness, breakage and split ends. So, please try to use it sparingly.
Additionally, if you want to reduce the damage from heating tools, you can also:
- Use foam rollers instead of hot rollers or curling irons (they’re surprisingly good!
- Use a diffuser attachment on your hair dryer to create curls without using high heat (or air dry or use the cold setting)
- Use a heat protectant no matter what you do
4. Chemical treatments can cause hair to become more curly with time
Chemical treatments like perms and relaxers will cause dramatic changes to hair texture – turning straight hair into bouncy curls. But how do these treatments actually work?
Perms are actually a more well-known type of chemical treatment for hair.
The process involves applying a solution that breaks down the hair’s natural protein structure and then wrapping the hair around rods to create curls.
Now, this solution is made up of an alkaline substance like ammonium thioglycolate which softens the hair’s outer layer (the cuticle) and allows the solution to penetrate the hair shaft. Once the hair is wrapped around the rods and the solution has had time to work, a neutralizing solution is applied to re-form the hair’s protein structure into its new curly shape.
Relaxers on the other hand are designed to straighten curly or wavy hair. This process also involves applying a solution that breaks down the hair’s natural protein structure just like a perm. But it’s combed straight later instead of wrapped around rods.
So, chemical treatments can cause hair to become curly.
5. Environmental factors may affect your hair texture
Now, genetics, hormonal changes, and chemical treatments are usually the primary reasons why hair changes texture – no doubt.
But environmental factors can contribute to this too!
Humidity is one major reason.
When there’s a lot of moisture in the air, it can cause the hair cuticle to swell and this can lead to frizz and curls. This is why many people experience “humidity hair” during the summer months when the air is more humid.
Do you remember Monica from friends having extremely curly hair when she goes to Barbados? Yup – that’s why.
If you live in a humid climate, you may find that your straight hair becomes wavy or curly despite zero changes to your hair care routine.
Another environmental factor that can lead to curly hair is more exposure to salt water or chlorine. If you spend a lot of time swimming in the ocean or a pool, the salt or chlorine in the water can dry out your hair and cause it to curl.
My partner developed super cute curls because he swims every day.
Now, if it’s the humidity, then here are some tips to combat the frizz and curls:
- Use a smoothing serum or oil: Apply this to your hair before styling to help control frizz and keep your hair looking sleek. Look for products that contain ingredients like argan oil or jojoba oil, which can help to seal the hair cuticle and keep moisture out.
- Use a diffuser when blow-drying: If you need to blow-dry your hair, use a diffuser attachment to help minimize frizz. The diffuser helps to distribute heat evenly and prevent the hair from becoming too hot, which can lead to frizz and damage.
- Avoid touching your hair: Touching your hair throughout the day can cause frizz and disrupt your style. Try to avoid touching your hair as much as possible and use a silk or satin scarf to protect your hair while you sleep.
- Try a humidity-resistant hairspray: Look for a hairspray that’s specifically formulated to resist humidity. These products are designed to help lock in your style and keep your hair looking sleek, even in humid weather.
- Consider a keratin treatment: Keratin treatments can help to smooth the hair cuticle and reduce frizz, making it easier to manage your hair in humid weather. Keep in mind that these treatments can be pricey and require some maintenance, so be sure to do your research and choose a reputable stylist.
6. Auto-immune disorders can cause hair to become curly
I’ve already talked a little about this under hormonal changes.
But let me explain this in a little more detail.
Autoimmune disorders are a group of conditions in which the immune system mistakenly attacks healthy cells in the body.
While these disorders can affect different parts of the body, they can also have an impact on the hair, causing changes in texture or even hair loss.
One of the ways that autoimmune disorders can affect the hair is through changes in hormone levels. Many autoimmune disorders are associated with changes in the levels of hormones like cortisol and thyroid hormones.
These hormones play a role in regulating the growth and texture of hair, so changes in hormone levels can lead to changes in hair texture or growth.
Cortisol is produced when you take a lot of stress – this can also lead to white hair.
Another way that autoimmune disorders can cause curly hair is through inflammation. Inflammation is a common symptom of many autoimmune disorders, and it can affect the hair follicles, leading to changes in hair texture and your hair becoming more curly.
While autoimmune disorders can cause changes in hair texture, you have to keep in mind that this is only a symptom.
If at all you feel like you may have an auto-immune disorder, please talk to a doctor. With the right care, you can definitely manage your condition.
7. You may have a nutritional deficiency
You need to understand that our hair and nails are made up of Keratin – it’s a protein. This requires certain nutrients to grow and stay healthy. Some of the key nutrients that our hair needs include protein, iron, and biotin.
Now, if we don’t get enough of these in our diet, our hair will start to become dry, brittle, and prone to breakage.
In some cases, this can lead to changes in hair texture, including curly hair.
Poor nutrition can also have an impact on hair texture. When we don’t eat a balanced diet, our body will prioritize other important functions over hair growth. This will cause hair to become thin, weak, and prone to breakage.
Certain medical conditions and medications may cause nutritional deficiencies that can affect hair texture. Some medications used to treat acne or high blood pressure can cause a zinc deficiency which is very important for hair.
So, if you feel this might be your reason – please check with a doctor and a nutritionist so that you can get the nutrients your body needs to maintain healthy hair.
8. Certain medications can cause hair to become curly
Some medications can affect the growth circle and cause changes in hair texture.
For example, some chemotherapy drugs can affect the growth phase of the hair cycle (Every hair strand has 3 phases – growth, rest, and shedding) causing hair to become very brittle, curly, or even fall out.
Sometimes even birth control pills or hormone replacement therapies can affect hormone levels in the body, which can in turn affect hair texture.
When an Instagram Influencer (@alex1leg) underwent Chemotherapy, his hair became curly – he sports it very well and I love his content.
If you are experiencing changes in hair texture while taking medication, please talk to your doctor. They can help you determine whether the medication is causing the change and whether there are alternative medications and treatment options available.
9. Your hair might just be changing naturally
Now, it’s actually quite common for hair to change texture with age.
One of the main reasons why hair texture changes with age is due to hormonal changes.
But additionally, as we age, the structure of our hair follicles can change. The hair follicle can become smaller, which can cause hair to become thinner and finer.
Sometimes, the hair follicle can become larger, which can result in thicker and coarser hair.
Additionally, constant exposure to UV radiation, pollutants and other lifestyle factors like diet and stress can cause your hair to become curly quite naturally.
How do I stop my hair from turning curly?
1. Identify the cause
Before you try doing anything to your hair, identify the cause.
I’ve listed about 11 causes above.
If any of those factors are causing your hair to become curly, then you can move to step 2.
If you are still unable to identify what could be causing your hair to turn curly, then consult a dermatologist, trichologist, or hair specialist to find out why your hair is developing curls or waves.
They are professionals who specialize in the health and care of hair.
They may be able to help you understand why your hair is turning curly.
They’ll perform physical examinations of your hair and scalp, ask about your medical history, and may even conduct some tests.
2. Avoid excessive styling
Heating tools like flat irons and curling irons do more damage than you think. They alter the hair structure with prolonged use as I mentioned before. Try to limit your use of these tools and if at all you do use it, please use a heat protectant spray to minimize the damage.
3. Use gentler hair products
Harsh shampoos and conditioners will strip your hair of its natural oils and this will cause it to become dryer and more frizzy. Study your hair type and look for products that are designed for your hair type.
Consider a deep-conditioning treatment (this deep conditioner is amazing!) every week or every once in 2 weeks.
I always read the reviews on Amazon for any product I’m purchasing and see photos of real people using the products to understand if it’s the right product for my hair type.
4. Eat a healthy diet
A balanced diet includes plenty of protein, vitamins, and minerals that will keep your hair healthy and strong.
Make sure that you are eating a variety of foods like a lot of pulses, fruits, and vegetables.
5. Talk to your doctor
Now if you are experiencing sudden and unexpected changes in your hair texture, please talk to your doctor.
They can help you determine whether there is an underlying medical condition that needs more looking into.
Here are a few more posts you may find helpful:
- How to Stop Hair Bleach from Burning Skin
- How to Protect Your Hair from Chlorine Without a Swim Cap
- Is it Bad to Touch Your Hair a Lot + How to Stop Touching Your Hair
- Should I Wet My Hair Before Cutting? All You Need to Know
- 12 Surprising Benefits of Rose Water for Hair + How to Use It
- 11 Genuine Reasons Why Your Hair is Sticky after Washing
- 9 Reasons Why One Side of Your Hair Grows Faster
- 7 Real Reasons Why Your Hair is Getting Shorter Without Cutting It