What causes straight hair to become curly

By: | Last Updated: March 5, 2022

What if one day you look at the mirror and realize you now have curls you do not intend to have? It would, at least, solicit some panic. You may decide to hide it with a hat and hope it will disappear. But, it may not.

This has become an everyday dilemma for you. What causes straight hair to become curly? Particularly, what caused yours? 

In this article, you may find out that the reason is universal, i.e., you just happen to be a woman. Or you might start pointing out the external influences you didn’t know could affect you significantly.

Why does straight hair become curly?

Why does straight hair become curly

To understand why straight hair can become curly overtime, you need to ask yourself first what makes hair curly. 

Follicle shape

Hair anatomy is as intricate as anything in your body. It might be a bunch of dead cells we casually style here and there but, in your hair shafts lie tiny holes which plays a big role to why your hair is curly— the follicle. Curly people have oval-shaped follicles while straight hair have round ones. The oval shape also leads to the formation of elliptical hair fibers which bends easier than round ones. 


Ultimately, your genes would determine if you will have curls or not. Your parents, your ethnicity to be exact, contributes to the hair type you will get. For example, Asians were found to have a gene variation which influences straight hair production. 

Your hair shape isn’t only determined when your body starts producing hair but in every hair growth cycle. Each hair has a growing phase of 3-5 years before it enters the resting phase. Interestingly enough, it can also be affected by your environment. So while your hair shape is likely to be the same for the rest of your life, some external factors may change it as it undergoes rebirth. 

One cool thing about genes, though, is that they can be a switch— they turn on and off. 

For example, if you had observed your mother having curly hair while you have a straight one, it might be that your “curly hair” manual is present but not yet activated. It’s a dormant volcano, basically. You just wait for something or some things to push it to the edge. 

Why is my straight hair turning curly?

Why is my straight hair turning curly

Raise your hand if you also did not know that all this time, your hair can turn curly on its own! No perms, no foam rollers, and no voodoo you had to do in the middle of the forest just to get those curls. Just plain old Time, serving you the change of hairstyle you wanted… or not.

Depending on how you take it, it is already there, and this almost-magical turnabout has happened to you. Before you buy different products altogether for your new hair, you should look first at the possible reasons for the change. Who knows? It might be something reversible. So, hold on to your wallet and read further. 


Hormones play a crucial role in gene expression. Hormonal fluctuations linked with puberty, pregnancy, and menopause can cause a drastic change to your genes, therefore, your hair shape too. 

Puberty can undoubtedly be life’s biggest curse or the most awaited glow-up. It feels like that, at least when you are a teenager. 

Your skin changes and you might even notice, to your utmost horror, you are getting hairier! Androgen is the hormone responsible for that. For ladies, the increase of androgen contributes to a flatter follicle and curlier hair. 

For most women, pregnancy, and menopause create a more significant impact on their hair than puberty. 

During pregnancy, the anagen phase becomes longer which means hair continually grows as estrogen increases. After pregnancy, estrogen levels drop and continually does during menopause. Androgen hormones become prominent at this stage, hence, the change you may notice in your hair strands. 

Hormonal shifts do not only occur in women. They can also happen during illnesses. 

For example, thyroid abnormalities lead to lack/ excess of thyroxine and triiodothyronine. This eventually leads to hair loss as the hair becomes brittle. 

Studies also found that those suffering from pre-diabetes or type 2 diabetes developed androgenic alopecia also. Extreme hair loss is not an indicator of a change in hair shape, but it might be a trigger. 

The following factors discussed will similarly have an indirect correlation. 


Aging rarely becomes a primary factor in having your straight hair turn curly. However, if you have had barely noticeable curly or wavy hair since you were young, it might be more apparent now that you are older. As you age, your hair becomes thinner and finer.

It’s like a jack-in-the-box toy, you see. Take away the volume which weighs it down, and your hair “springs” and looks like it changed to a curlier shape when in fact, it’s just hidden. 

Diet and Medicine

The effect of diet or medicine on hair shape is much like aging. It does not have a cause-and-effect relationship with hair shape. However, vitamin and mineral deficiency causes certain hair problems like hair loss. When you suffer hair loss, your hair may appear wavy as it has become lighter. 

This is also the case when you take medicines. Certain metals, like zinc, may contribute to hair loss too. Copper peptides were also found to thicken hair strand which might be induced by change in follicle shape. 


Having curls due to a change of climate isn’t breaking news. Humidity has long since been the greatest villain in the story. The moisture in the atmosphere bonds with the proteins in your hair, causing it to curl and frizz

As recent studies suggest, other environmental aggressors like air pollution cause a hormonal spike. This leads to a decline in your scalp health and, consequently, your hair. 

Chemical treatment 

When something as tame and gradual as a diet can change your hair shape, it might not come as a shock at all that relatively harsh chemicals induce hair change. 

Perm uses highly alkaline chemicals and hydrogen peroxide to restructure the follicle and the protein bonds in your hair strands. This may be an irreversible step even when you decide to grow out your hair. 


Now, no need to get anxious at this new hair of yours. If you only knew how to care for straight hair all your life, then this is a chance to learn something new! 

One essential tip for your new curls is to moisturize them. Your natural oils may have difficulty reaching your hair tips with this hair type. So invest in deep conditioners and start searching for new styles which suit your curls better. 

Best of luck to you!


Why is my hair getting curlier?

Why is my hair getting curlier

If you have wavy or curly hair from the dawn of time and observed that it has turned even curlier, you have a list of reasons to check. 

First, it might be midlife curls. Yes, such a dilemma exists as you get older and your hair starts thinning

The next big factor for this obvious change is increased humidity. If you have curly hair, you know all too well that very humid areas make your hair curlier and more frizzy

So monitor the hygrometer, and you might as well check your overall mental and physical health. The body is fantastic at dealing with internal fluctuations, but the changes can be drastic once it topples over. 

Can stress cause straight hair to go curly? 

Stress changes the hormone level in your body. Whether mental or physical, stress may aggravate current illnesses and lead to overall health decline. Hair loss is a common consequence. 

During stressful times, the hormone cortisol increases in your body. This leads the hair to stay more in the telogen or shedding phase. Alopecia may make less wavy hair more apparent. However, the loss of volume could also make straight hair appear flatter.

It’s a case-to-case basis. If you have underlying curls, it may come out as magically having curly hair. 

Can naturally straight hair turn curly? 

Yes, it can. If your parents gave you a recessive gene for curly strands, it means your hair has the possibility of turning curly. It’s not a 100% prediction, though. After all, that gene may never be switched on in your lifetime. 

So, it really all depends on what set of genes you have. Ladies are also more impacted by hormonal changes. The change in muscle tone in the scalp may lead to a change in follicle shape. 

CHECK OUT: 8 Ingredients To Avoid In Hair Products For Curly Hair

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