Why Are Some of My Hairs Thicker than Others?

By now, I’m sure you’ve already figured out that no one else in the world knows whether you have thick or thin hair more than you do. Since your hair’s growing on nobody else’s but your head, I’m sure you’ve had enough experience styling and managing them to at least have a gist of what kind of hair texture you have.

If you need to put some effort into combing through your hair (even without tangles), chances are you have thick hair. On the other hand, if you have less hair to brush, chances are your hair’s much thinner. But did you know that individual hair strands can come in different sizes, and some hair strands can be thicker than others?

While genetics plays a huge role in influencing most of your traits, even how thin or thick your hair is, there are other possible reasons why the texture of your hair strands is uneven. In this article, we’ll look at a few more reasons why some of your hair strands are thicker than others. So don’t stop reading now if you want to know more!

Before we dive right into the possible reasons behind some of your hair strands being thin and some being thick, let’s first briefly go over hair—specifically, what it is, what it’s made out of, how it grows, and why we have it.

What is Hair?

Ah, hair. It grows almost everywhere—from the top of our heads and down to our toes. But what exactly is it?

Hair is a protein filament or a fiber growing out of the epidermis, the outer layer of skin in your body. It’s one of the most defining or distinguishable characteristics of mammals, like humans, as it covers almost our entire body except for the palms of our hands, soles of the feet, and lips.

Now that you know what hair is, let’s answer the question:

What Makes Up Our Hair?

According to Matthew Hoffman, MD, hair is made of a tough protein called keratin. If you aren’t well familiar with the terms protein and keratin, worry not because I’ll briefly explain what they are to you.

Protein exists throughout the body. It does most of the work in our cells and can be found in our muscles, bones, skin, hair, and virtually every other body part or tissue.

Because protein makes up the enzymes that power many chemical reactions inside us and even the hemoglobin that carries oxygen in our blood, it is responsible for making us what we are and keeping us that way.

Keratin, as I said above, is a protein. As a protein naturally produced by our bodies, keratin helps form hair, nails, and the skin’s outer layer (epidermis).

Keratin provides support and protection to our bodies. Because keratin is so strong, it doesn’t dissolve in diluted acids, alkalines, solvents, water—or any other chemical in our bodies. And our hair, nails, and skin rely on the amount of keratin in our body for their overall health.

Now that you know what keratin is and that it makes up your hair, let’s move forward to answer the question:

How Does Hair Grow?

According to Matthew Hoffman, MD, hair grows at different rates in different people, and the average growth rate is roughly a half inch per month. But generally, hair growth occurs in cycles. And according to him, these cycles consist of three phases:

• Anagen (the growth phase): In the anagen phase, most hair strands start growing at any time, and each one spends several years in this phase.
• Catagen (the transitional phase): Over a few weeks, hair growth begins to slow down, and the hair follicle shrinks in this phase.
• Telogen (the resting phase): In this phase, hair growth stops, and the old hair detaches from the hair follicle over months. And new hair in the growth phase will start pushing out old hair in this phase.

Now that you know how hair grows, even its three phases, let’s figure out why it does just that. Let’s find out the purpose of our hair by answering the question:

Why Does Hair Grow?

Hair has several purposes, including sensory input, thermoregulation, and communication, but its primary purpose is protection.

For example, the hair on our head protects our skull from the sun’s heat and UV rays. Another example is that the hair growing around our eyes (eyelashes) and the hair growing inside our nose and ears protect us from allergens and germs in the air. They do this by trapping and eliminating these germs and allergens. Our eyebrows prevent sweat and other particles from dripping into our eyes and irritating them.

Now that you know what hair is, what it’s made out of, how it grows, and why we have it, we can now answer the question:

Why Are Some Hair Strands Thicker Than Others?

1. Genes and Hormones

If you’ve already read our article, “Why Do My Sideburns Curl,” you probably already know that our genes and hormones influence how our hair grows.

Proof of genes playing a role in hair thickness is that scientists have associated variations in genes called the EDAR and FGFR2 genes with differences in hair thickness among Asians. They also associate a polymorphism in another gene called TCHH with differences in hair texture among Northern Europeans.

Proof that hormones play a role in influencing the thickness of our hair is that when people have high androgen hormones, like DHEA and testosterone, they experience excess hair growth, especially on the body or face. And when people have low androgen hormone levels, they experience hair thinning and even hair loss.

Many other hormones affect hair thickness, and you can check them out in this study: Hormonal Effects on Hair Follicles – PMC

2. Hair’s Already Grown Out

As I said above, hair growth occurs in cycles and has three phases. Since you already know about the hair growth cycle, I’m sure you can imagine that the hair on your head, especially the ones already grown out, has been around for some time to be exposed to many damaging factors.

Damaging factors such as toxins, harsh winds, extreme cold & hot temperatures, chemicals, and dyes strip our hair of its protective outer layer (the cuticle). Because of this, when our hair’s already grown out, it becomes thinner, more prone to split ends, and sometimes can even break off.

3. Poor Diet

I’m sure you’ve already heard the saying, “you are what you eat.” That same saying applies to how the food you eat affects or influences your hair growth, including its texture.

If you eat food rich in nutrients like keratin that make your hair shiny and strong, you’re sure to have thicker and healthier hair. On the other hand, if you eat unhealthy food that you’ll barely get any nutrients from, you can expect hair thinning to happen.

When it comes to living an unhealthy lifestyle, sleep deprivation and too much alcohol intake can lead to many health issues, such as dehydration. Severe dehydration’s known to cause and even accelerate hair loss.

4. Hair’s Damaged

While many existing environmental factors already cause damage to our hair, like extreme cold and hot weather, sometimes our hair gets damaged because of our own doing. Some things we do that damage our hair include the following:

• Using hair products that contain harmful chemicals or components, like sulfates and parabens.
• Over-brushing.
• Using hair ties that pull tightly on the hair or tie your hair in tight hairstyles.
• Rubbing your hair harshly with a towel to dry it.
• Using heat to style or manage your hair (blowdryers, straightening, and curling iron).

5. Hair Thickening Products

People dealing with hair thinning or loss can resort to buying and using hair-thickening products to solve their problems. While there are effective products, they can leave people with uneven hair strands if they aren’t used or applied correctly.

In cases where people fail to apply the hair-thickening products they use to their hair or scalp evenly, they’re bound to have uneven hair too. The hair strands growing in the sections or areas with more products to absorb will likely be thicker.

6. Hair Conditions or Disorders

While not many know this, certain hair conditions or disorders can cause uneven hair growth and texture. At times, receiving or undergoing medication for these conditions can also be a reason for some hair strands to grow thicker than others. Here’s a list of some hair conditions that can cause uneven hair:

• Alopecia areata. Round patches of total hair loss, usually from the scalp. The cause of this hair condition is unknown up to this day, and the patient’s hair usually grows back.
• Male pattern baldness. The most common type of hair loss in men. This condition usually includes either a receding hairline, hair loss at the crown, or both.
• Female pattern baldness. In women, hair loss usually includes hair thinning across the scalp, with a preserved hairline. The crown of the head may be affected, but hair loss rarely proceeds to baldness the same way it does in men.
• Tinea capitis (ringworm). Patches of hair loss due to a scalp fungal infection. While the patches of this condition appear in a ring or circular shape, there isn’t an actual worm involved.
• Trichotillomania. A mental disorder that makes patients have an irresistible urge to pull out their hair. The cause of this condition is also unknown up to this day.
• Telogen effluvium. The falling out of hair in large patches, usually a month or two after experiencing a personal shock (such as surgery, childbirth, or severe stress).
• Postpartum alopecia. Hair loss after delivering a baby- is a form of telogen effluvium.
• Folliculitis: The inflammation of hair follicles because of an infection.

• Piedra (trichomycosis nodularis): A fungal infection of the hair shaft. Hard nodules of fungus cling to hair fibers and can sometimes cause hair loss.

Final Thoughts

The first step to knowing how to solve your hair problems is knowing what’s causing them. Whether you have naturally thin or thick hair, there’s no doubt that having uneven hair strands is super frustrating.

So the next time you notice some of your hair strands are thicker than others, consider using this article to determine what’s causing them to be that way, then look up some solutions to those reasons or problems.