The Highlights:
  • Hair thinning for women is a result of the hair falling out faster than it regrows. It's normal to lose hair every day, but it should ideally grow back at roughly the same rate.
  • Causes for low hair-growth / fast hair-fall can be can be categorised into two groups: genetic hair thinning or reactive hair thinning.
  • Genetic hair thinning is when your hair thins as a result of your genetics. These changes can take place later in life and would be seen as 'age related'. Reactive hair thinning is when your body reacts to external factors.
  • Reactive hair thinning causes include; illness, stress or trauma, diet and nutritional deficiencies (iron, vitamin b12, etc.), pregnancy, weight loss induced hair thinning and illness (thyroid, etc.).
  • Therefore, hair thinning should not be ignored as it could be a sign of a bigger health issue. So it makes sense to pay attention and be proactive (but avoid stressing about it if you can).
  • If you experience hair thinning, review your diet (consider a blood analysis to identify nutritional deficiencies), minimise stressors, exercise moderately.
  • Speak to your doctor to eliminate the chances of any underlying illnesses. And be careful when you style your hair to avoid excessive damage.

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

And 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.

Science: How Hair Grows And How To Make It Faster

what causes thin hair


What causes thinning hair for women?

Simply put, thinning hair is caused by hair loss (duh). But 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 Next: How To Make Thin Hair Look Thick

what causes thin hair

The THICK Halo in col. Platinum Blonde #60

Genetic hair thinning

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 thinning 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 thinning

And if it's not genetic, then it's likely to be 'reactive'.

Reactive hair thinning (as the name would suggest) is when your hair is thinning over time as a result of external factors outside of your genetics.

This can include factors such as diet, stress, nutritional imbalances, trauma, or illness, to name a few. 

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

Why hair thinning really matters

When we think about hair thinning we often make the mistake to think of it as a trivial issue; like something that only has superficial value.

But in actual fact it's much more significant than that.

Think about it:

If you were to be ill, deficient in necessary nutrients, or suffering from stress or anxiety, what would be the first are that your body would stop funneling it's precious resources to?

Your non-vital aspects, like the epidermis (outer skin layer), hair and nail growth.

So this can be a sign of something bigger - like a warning. Therefore we must pay attention.


When a woman suffers from hair thinning, she's suffering a deep blow to her sense of confidence and attractiveness.

Call this superficial all you like, but any woman who has ever experienced hair thinning, or knows someone who has experienced hair thinning, knows it's not a small matter.

It's often deeply upsetting and sometimes embarassing.

So now that we have set the premise, let's explore the most common causes of hair thinning in women:

The most common causes of hair thinning for women

The remainder of this article is going to be focused on reactive hair thinning, since these are the factors that are somewhat within our control.

So, let's explore these in the section below.

Hair thinning caused by illness

Illnesses of various sorts can set in motion a complex chain reaction of changes in your body.

In many cases this can result in your skin, nails and hair suffering from it's natural lustre.

And although extreme illness can be the main culprit of hair thinning, mild illnesses can have lasting effect on your hair's thinning activities as well.

These illnesses can include Lupus, Alopecia and other types of illnesses, that almost specifically and consistently targets your hair growth.

Try this: How Scalp Exfoliation Can Fix Your Hair Drama

Hair thinning from pregnancy

When a woman goes through pregnancy she will go through a remarkable physical change, in ways that cannot be summed up in this article.

But to say the least, her hormones will change as she stops living for herself and starts living for her child.

The changes in hormones on their own can cause disruption to her hair growth, which may lead to hair thinning.

Additionally, as her body is the incubator for her unborn child, the body will prioritise funnelling resources to the baby before hair growth.

Post-pregnancy hair thinning is a real thing too, and can last for some years to come.

Also read: 8 Common Causes of Hair Loss in Women

Trauma induced hair thinning

Conditioner such as Telogen Effluvium can cause significant hair thinning for women. This condition is caused when a person is under significant stress such as during a traumatic experience.

The body will begin to shed hair at a faster than normal rate, leading to a thinning of the hair at the root.

Whereas Anagen Effluvium is a similar condition affecting the hair follicles natural growth cycle. This can also be caused by trauma. Anagen Effluvium is when the hair follicle stops in it's Anagen stage of the hair growth cycle, and stops producing new hair. Yet the existing hair will continue to fall leading to hair thinning.

Hair thinning caused by 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.

Read next: Try this protein packed hair treatment with egg

what causes thin hair

Hair thinning from stress

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 next: 7 Foods you're eating that are killing your hair

what causes thin hair

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

Hair thinning caused by extreme 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.

Popular: 10 Ways To Detox Your Hair To Make Your Hair Grow

what causes thin hair

Hair thinning from 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!

Also read: How a "healthy diet" can cause hair loss

what causes thin hair

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

Hair thinning from 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.

Hair hack: How rice water shampoo can help you grow your hair

what causes thin hair

Hair thinning from 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)

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

Age related hair thinning

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 at 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 next: 10 Healthy Hair Tips To Bring Your Hair Back To Life

How to stop hair thinning?

To understand how to prevent hair thinning for women, you need to know what causes it.

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

Then do the following:

what causes thin hair

1. 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!

Read next: Hair Loss Serum - Top 3 Powerful Solutions For Regrowth

what causes thin hair

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

2. Is your diet causing your hair to thin?

It may be time to review 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? Specifically keratin.

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 increase 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, pumpkin, sweet potato, cauliflower 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.

Also read: Why Jamaican Black Castor Oil Is Incredible For Hair Growth 

what causes thin hair

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

3. Exercise in moderation can reduce hair thinning

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.

BUT do so in moderation. Extreme exercise can lead to extreme weight loss which is an almost guarantee for exacerbating hair thinning in women.

Hack: Protective Sleep Hairstyles To Avoid Hair Damage

what causes thin hair

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

4. 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.

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.

Hair Hack: How To Create Heatless Curls

what causes thin hair

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

5. Stress less to recover your hair

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.


Read next: How to hydrate hair after bleaching

what causes hair loss

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

6. Take the right supplements

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.

But don't substitute a good diet with supplements. The best way to get your nutrients is still through whole foods.

Also read: The best hair extensions for thin hair

what causes thin hair

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

7. In the short-term: 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.

How to make your thin hair look thicker

If you are suffering from thinning hair as a woman then some of the suggestions above will no doubt be of use to you.

But while you're getting your hair back on track, there is a solution that you can use to make your hair look thicker, longer, healthier and 100% natural.

This solution will cause ZERO damage to your own hair and it won't break the bank. It's easy to use, takes almost no time at all, but it will give you your dream hair back in an instance.

It's called; The Halo.

Watch this video below for a quick introduction to The Halo Hair Extension, and learn why more than 60,000 women all over the world have decided to kick thin hair to the curb with this miracle solution.