Unfortunately, there is no one size fits all answer to what causes thin hair.

Just as there is no one size fits all answer to fixing thin hair!

However, that does not mean you are doomed to thinning locks forever.

Thankfully, there are many causes of thin hair and equally as many ways to combat it.

To help you get your thick locks back, or to achieve thick hair for the first time, I have rounded up the top causes of thin hair, and some of the easiest ways to fight it.

what causes thin hair

What causes thin hair?

Simply put, thin hair is caused by hair loss.

However, the cause of hair loss is not simple.

In fact, there is a multitude of different reasons that your hair could be thinning.

Each cause of thin hair can be split into two categories; genetic and reactive hair loss.

Read Thin Hair? Here's What To Do

what causes thin hair

The THICK Halo in col. Platinum Blonde #60

Genetic hair loss:

So what causes hair loss?


Just like our skin and metabolism, you're either genetically blessed or cursed with good or bad hair genes.

(Shout out to mum and dad for the fact I put on weight from looking a piece of bread)

Genetic hair loss means your hair will gradually become thinner over the course of your life.

Genetic hair loss is usually caused by a sensitivity to certain hormones, specifically androgen (the male hormone).

This genetic predisposition causes your hair to grow back thinner and shorter with every passing hair growth cycle.

Reactive hair loss:

Just because you might be one of the lucky few genetically blessed with thick luscious locks, does not mean you are safe from thin hair.

So what else causes thin hair?

Internal or external factors such as diet, stress, nutritional imbalances or illness can be just as detrimental to our hair growth as our genetics.

Read 10 Hair Loss Home Remedies You Can Do Right Away

what causes thin hair

@ayanahairdesign wears the MEDIUM halo in col. Beige + Dark Blonde 613/10

Most common causes of hair loss

Hormone imbalances:

Hormones are pretty much responsibly for all of our problems.

**Crys after dropping a spoon.

So it's no surprise that hormonal imbalances are one of the leading causes of thin hair in women.

Hormones help to regulate the hair growth cycle, so if they're out of whack, so are your locks.

Hormonal hair loss can be considered both reactive and genetic.

However, those with a genetic predisposition to follicle sensitivity will be affected by a hormonal imbalance far worse than someone without one.

what causes thin hair


**Tears own hair out.


Stress is considered a reactive form of hair loss, however, it again presents much worse in those with genetic sensitivities to androgen.

This is because stress triggers the body to produce higher levels of the male hormone causing finer and shorter hair growth.

It can also trigger a hoard of other issues that wreak havoc on healthy hair growth such as insomnia, scalp sensitivities, dandruff, and digestive issues.

Also if you're anything like me, stress destroys your diet.

**inhales a pint of ice cream in 2.5 seconds.

Which, as well know, a healthy diet means healthy hair!

Read 7 Foods you're eating that are killing your hair

what causes thin hair

@chontelleberryman wears the FINE halo in col. Platinum Blonde 60.

Changes in weight:

While shedding some extra kgs (if necessary) is great for your overall health and wellbeing, sudden and dramatic weight loss can also cause your hair to shed.

Excessive hair loss can occur 6-12 weeks after you've lost serious weight.

So, what causes hair loss during weight loss?

The answer here lies in nutritional imbalances.

This is why it is very important to lose weight properly, focusing on healthy, balanced meals rather than extreme calorie-cutting or fad diets.

Losing weight too fast is not only dangerous and more difficult to maintain but, it is also horrible for your hair.

So if you're trying to drop a few pounds, be patient and stay healthy, the kgs can come off without your hair following suit.

what causes thin hair

Anemia/Iron deficiency:

If like me, you're blessed with an iron deficiency, you know how fun it is.

**gets dizzy standing up.

***Looks like I've never seen the sun.

****All my foundation shades range from snow to classic ivory (might as well be called ghost)

****Will punch the next person who tells me to "eat a steak."

****** Has constantly thinning hair.

I know right!?

As if anemia wasn't fun enough already, but did you know it might actually be what's causing your hair thinning too?

So, what causes thin hair if you suffer from anemia or an iron deficiency?

Well, iron is essential to building healthy and strong hair, so without it, your locks will be a little lapse.

Iron deficiency is actually one of the most common causes of thin hair in women!

So, get your blood tests and eat your spinach ladies!

what causes thin hair

The FINE halo col. Beige Blonde + Dark Blonde 613/10

B12 deficiency:

A little known, but equally as common kind of anemia, is B12 anemia.

Vitamin B12 deficiency is similar to iron deficiency as it causes low energy and a heap of other fun stuff.

It also, just like iron anemia, causes hair loss.

So, how does a B12 Deficiency cause thin hair?

B12 is very important in the production of red blood cells which carry oxygen around the body.

A lack of red blood cells and a lack of oxygen is bad on many levels, particularly for healthy hair cell growth.

This is especially common for vegans and vegetarians as the easiest way to get vitamin B12 is through animal products.

But, I'm not suggesting you abandoned your dietary choices, just try to add some alternative sources of B12, such as plant-based milk, some soy products, fortified cereals, and nutritional yeast to your meals.

Or, take a daily B12 supplement.

Your body and hair will love ya for it.

Read Food For Thought: Is Your Diet Good For Your Hair?

what causes thin hair

Thyroid issues:

The thyroid is often associated with problems losing weight, but it is also a known culprit with problems losing hair!

(If only we can swap the hair loss and the weight gain around, am I right ladies?)

There are two kinds of thyroid conditions;

Hyperthyroidism: overactive thyroid gland


Hypothyroidism: underactive thyroid gland.

Both an under and overactive thyroid can cause hair loss.

The thyroid gland regulates metabolism, controlling the production of proteins and tissues used for oxygen.

Which is why a thyroid imbalance affects the hair cells.

Untreated hypothyroidism can also cause anemia, which, as we now know, also causes thin hair.

The only way to diagnose thyroid imbalances is through medical testing.

So, if you suspect your thyroid gland might be acting up, definitely book an appointment with your GP.

what causes thin hair

The THICK Halo in col. Cream Blonde #20C.


From becoming more self-assured to having financial security, there are so many great things about getting older.

But, our metabolism and hair often refuse to play the game and want to peak around 22.

Fortunately, you may still have a few years before your hair decides to follow your metabolism (and ability to recover from a hangover) and jump ship.

In fact, age doesn't usually cause hair thinning until we are close to menopause.

Our hair becoming thinner with age is inevitable, and nothing to worry about.

It is all part of the natural ageing process, so don't fight against it too hard, or with too many chemicals.

Read 10 Healthy Hair Tips To Apply To Bring Your Hair Back To Life


How to stop hair thinning:

To understand how to prevent hair loss, you need to know what causes hair loss.

While I have covered that extensively approve, you need to identify what particular problem is causing YOUR hair to thin.

what causes thin hair

Pay attention to your hair

The easiest way to work out what causes thin hair for you is to pay attention to your locks.

Hair loss doesn't just happen, it is usually a gradual process that goes along with our natural hair growth cycle.

In fact, it can take up to three months for the hair to start thinning once it has been triggered.

A small amount of hair loss is natural and nothing to panic about!

In fact, try not to panic even if your hair loss is excessive, as this can make matters a lot worse!


The first step would be seeing your GP to address any underlying health problems that may be causing hair loss.

A professional can help you figure out if your hair loss is genetic or reactive and the best route to treat it.

In most cases, the hair will begin to grow normally once the problem has been treated!

what causes thin hair

@shannontayloor wears the THICK halo in col. Beige Blonde + Dark Blonde 613/10.

Change your diet


Your diet is so important to your hair, health and wellbeing in general!

Food is the best medicine.

And we all know that bad food causes bad hair.

So what causes thin hair when it comes to food?

Well, there are two major food groups that your hair requires to grow;

Protein is one of these.

Did you know your hair is made of protein?

This is why adequate protein intake is so important for healthy hair cell production.

I'm not saying you have to stick to a diet of meat and veg.


Simply up your daily protein intake by including a palm-size portion of protein in at least two meals a day.

Obviously lean meats are a great protein choice, but you can also go for tofu, legumes or yogurt if you're a vego.

A smoothie or some oatmeal with a scoop of protein powder is also a great breakfast alternative.

Another food group which is essential to healthy hair growth is complex carbs.

Seriously, if anyone ever tells you to completely cut out carbs, punch them in the face and walk away.

You don't need that negativity in your life.

But what you do need in your life, is complex carbohydrates.

These provide your hair with the energy that it needs to grow.

Now, unfortunately, I'm not saying you can eat pasta for every meal.


But snacking on health carbs like fresh fruits and whole wheat crackers is enough to give your hair an energy boost.

Be careful of your carb consumption however, as too many can have some seriously detrimental effects on your locks too.

Read 7 Foods you're eating that are killing your hair

what causes thin hair

@sshelbs wears the THICK Halo in col. Dark Blonde + Light Brown #10/6


Exercise has immense benefits when it comes to combating hair loss.

On its own, exercise helps with a healthy hair growth cycle as promotes blood flow into the scalp and circulation.

This results in the formation of healthier hair cells.

Exercise also helps to combat many of the common causes of thin hair such as;

hormonal imbalances, thyroid problems, poor diet, age and stress.

So get out for that run girl, your hair depends on it.

what causes thin hair

@sofiajamora wears the THICK halo in col. Beige Blonde + Dark Blonde 613/10. Styled by @ashleyantoinebeauty

Take care when styling

Drop it like its hot!

Unfortunately, your hair will drop it it's too hot.

So get smart about styling.

Heat damage is obviously a huge cause of hair loss so always use your heat protection spray and turn your styler down a few notches.

Read Hair Hack: How To Create Heatless Curls

Also, as hard as this might be to hear, avoid the top knot.

Hairstyles that pull your hair back tightly place traction on your hair follicles.

This can stress your strands and cause them to fall out or break off.

So, try cutting down on the high ponies and messy buns.

Instead, opt for gentle silk scarfs, headbands or clips to keep your hair out of your face.

what causes thin hair

@mikkiauldhair wears the MEDIUM halo in col. Beige Blonde + Dark Blonde 613/10.


Sounds fake, I know, but it is in fact possible to not be a ball of stress all the time!

Seriously, just stop and take a deep breath!

Deep breathing is one of the most powerful ways to calm the F@*# down.

Short shallow breath triggers our bodies stress response, so it is import to make sure we are regularly taking long deep diaphragmatic breaths.

This lets our bodies know that we are safe and all is well.

Which, keeps those pesky little anxiety-ridden stress hormones at bay.

Exercise, yoga, diet and mediation are also great ways to cut down on your stress.

If you seem to be stressed out a great deal of the time, chat to your GP.

An underlying anxiety disorder might be rearing its ugly head.

This is nothing to be embarrassed about, but it is very important to get checked to and manage correctly.

If you're currently feeling stress out...Here is a cute puppy.


what causes hair loss

@stephaniemaii_x wears the THICK halo in col. 613/10.


Supplements are a super-easy way to combat nutritional and vitamin deficiencies as well as hormonal imbalances that may be causing your hair to thin.

Supplements will work best when taken along with a healthy diet and exercise routine.

The best supplements for thin hair are ones including; iron, Vitamin C, Vitamin B12, Vitamin D3, Copper, Zinc, Selenium, and the essential amino acids, L-Lysine and L-Methionine.

Read How To Master Your Hair Care Routine Once And For All

what causes thin hair

@amybaineshair styling the MEDIUM halo in col. Light Brown 6.

Use a Halo for extra volume

Repairing thin hair can take some time.

So in the interim hair extensions might be worth considering to make your appear thicker and healthier.

However, certain permanent extensions such as microbeads and tape-in extensions can do more harm than good when it comes to your hairs health.

Non-permanent extensions such as halos and clip-ins are definitely the way to go for damaged hair.

However clip-ins can also cause breakage, contributing further to your thin hair problems.

Halo hair extensions are a completely safe and non-damaging option when it comes to getting your luscious locks back...or at least looking like you have.

Read The Average Cost Of Hair Extensions (And Things To Be Careful Of)

what causes thin hair

@chloe_park_ wears the THICK halo in col. Medium Brown 4.

Sitting Pretty Co-Founder, Taryn talks about why the halo is the best extension for this hair