Causes

Why is my hair falling out? 

Woman looking upwards at her hair

Hair falling out is a normal part of your hair cycle, and you can expect to lose around 50 to 100 hairs from your head every day! However, if your hair is falling out and is not being replaced by new hairs, then this is more concerning and this is what we refer to as hair loss. We’re going to look at the most common causes of hair loss in women, so that you can identify why your hair is falling out.

There are two types of hair loss that you need to know about: 

Genetic hair loss: this is caused by your genetics. Your genes are a blueprint for your body, and determine characteristics such as your hair colour and eye colour. They also determine at what rate your hair will fall out as you grow older. This type of hair loss is also known as female pattern baldness, and is the hardest type of hair loss to treat.

Reactive hair loss: this is caused by a reaction to a change in the body. This might include extreme stress, childbirth, hormone imbalances, vitamin and mineral deficiencies etc. This type of hair loss is independent of your genetics and is usually possible to correct.

Genetic hair loss

Hair life cycle diagram Anagen Catagen Telogen Exogen Growth Transition Resting Shedding

These are the stages of the natural hair life cycle. With female pattern baldness (androgenetic alopecia), the anagen (growth) phase is shortened and the exogen (shedding) phase is lengthened, causing premature hair loss.

Genetic hair loss is often referred to as female pattern baldness. This is the most common cause of hair loss in women, and almost all women eventually develop some level of female pattern baldness during their lifetime. This is a genetic (inherited from your family) form of hair loss, rather than being caused by something you have done or your environment. Female pattern baldness can begin at any time after puberty, but typically becomes noticeable around menopause. It is a gradual form of hair loss rather than a sudden loss of hair, and for women it is usually occurs around the crown of the head. The frontal hairline for women is unaffected.
 
The scientific term for female pattern baldness is androgenetic alopecia. It involves the actions of the male sex hormone, androgens, but the exact nature of their role in female pattern baldness is unknown. The hair loss is caused by a shortening of the hair’s growth phase (anagen phase) during the hairs' life cycle, and an increase in time between the shedding of a hair (exogen phase) and the re-starting of a new cycle soon after (anagen phase). This shortening of the hairs' life cycle means the hair follicles also change, becoming shorter and thinner in appearance. This means longer and thicker hairs are being replaced by shorter and thinner ones.

Although there is no cure for female pattern baldness, there are a variety of ways that it can be treated to slow down the hair loss and attempt to restore the lost hairs. Please refer to our treatments page to read up about different treatments for this type of hair loss. It is advised to start treatment as soon as possible when this type of hair loss is identified. Although female pattern baldness is almost always caused by genetic factors, there may also be an underlying endocrine condition which should be ruled out by your doctor. We have written a dedicated article about female pattern baldness here.

Reactive hair loss

There are seven different types of reactive hair loss (there are others, but they are less common). 

1. Traumatic events

Woman in bed with hair out

It is common for people to experience hair loss after a traumatic event, such as the following: 

  • Death of a family member 

  • Job loss 

  • Extreme and prolonged stress 

  • Infection/illness 

  • Surgery 

  • Crash dieting 

As you can see, these traumatic events cause very high levels of physical and/or mental stress on the body. The hair loss typically starts around two to three months after the traumatic event, and will rarely occur at the time of the actual event. It is identified by a sudden large loss in hair, to the extent that you may be pulling out clumps of hair from your head. You may find large amounts of hair on your hair brush, in the shower plughole, or on your pillow in the morning. The hair loss occurs all over the scalp, rather than being focused in any one place. 

 

The scientific term for hair loss after a traumatic event is telogen effluvium. The traumatic event causes a large number of hairs to prematurely move from the growth phase (anagen phase) to the resting phase (telogen phase). It is this shift in the hair loss cycle which means the hair loss occurs around two to three months after the traumatic event, as it takes time for hair to shed during the resting phase. A normal person should expect to lose 50 to 100 hairs from their head a day, but telogen effluvium may cause a person to lose up to 300 hairs a day. 

 

The good thing about this type of hair loss is that it is not permanent. Once the underlying cause of the stress has been resolved, the hair will grow back. This usually takes up to six months, but no treatment is needed – the hair will gradually grow back in volume and thickness. The only recommended solution is to try to identify the traumatic event, and find ways to healthily cope with its impact. Remember, the traumatic event would have happened around two to three months before your hair started falling out. You should still nourish and care for your hair by applying some of the products we have picked out here. We go into more detail about hair loss from traumatic events/stress in the following article

2.    Childbirth

During pregnancy, your body goes through lots of changes to support your baby. Your hair is no different. The surge of oestrogen (female hormone) in the female body causes a surge in hair growth, and your hair stays in the growing phase (anagen phase) for longer than it normally would. The result is that during pregnancy, your hair looks a lot thicker and fuller as it rapidly grows.


However, after childbirth the levels of oestrogen in your body begin to fall back to normal levels. As this happens, the hair returns back to its normal growth cycle and that thicker hair you had during pregnancy sheds. The hair typically falls out from across the scalp and may come out in large clumps. This type of hair loss also belongs to the same category as traumatic events, and is known as telogen effluvium. Although some women report that they have permanently thinner hair, most women's hair returns to what it was like before pregnancy. 


No treatment is required, as the hormones in the body will return to their natural levels after pregnancy. However, you should still nourish and care for your hair by applying some of the products we have picked out in the following article. We go into more detail about hair loss from traumatic events/stress here for further reading. If you're interested in finding out more about postpartum hair loss, click here. 

3.    Hormone imbalances

Pills to regulate hormones

Hormone imbalances can cause a number of different health issues, from rapid swings in your mood and mental state to weight gain, adult acne, fatigue etc. One of the most noticeable physical symptoms may be sudden hair growth or hair loss. Excess amounts of oestrogen in the female body causes a surge in hair growth, which is common during pregnancy. However, an excess of androgens has the opposite effect and may cause long term hair loss, as is typically seen with female pattern baldness.

Unfortunately, there is no single test that doctors can use to identify hormone imbalances. However, it will usually be accompanied with other often non-specific symptoms such as memory problems, mood swings, fatigue etc. With this type of hair loss, you should work with your physician to test and identify what type of hormone imbalance you are experiencing, and how you can work to correct this. We have explored some common hormone imbalances which may cause hair loss in the following article.

4.    Vitamin and mineral deficiencies
 

Just like hormone imbalances, vitamin and mineral deficiencies can cause a number of different health issues. The most common deficiency for women that causes hair loss is iron deficiency. This may be because your diet does not include enough iron, or your body is not able to use iron properly. Iron is needed to for the healthy circulation of blood and delivery of nutrients to your hair cells. Without good levels of iron your hair will begin to suffer. Research has shown that in most cases, hair loss related to iron deficiency does not cause permanent damage. Therefore, we recommend that if you suspect you have iron deficiency, talk to your doctor to get a blood test and determine if it is the cause of your hair loss.


There are lots of other types of vitamin and mineral deficiencies that may be causing your hair loss which can be determined by blood tests, and we have gone into more detail on how to identify this type of hair loss here. Luckily, hair loss caused by low levels of vitamin and minerals is typically temporary and will resolve once you have corrected your deficiency.

5.    Illness
 

Hot beverage next to bed

Suffering from an illness can cause significant physical stress on the body’s immune system, which may result in hair loss. This is known as telogen effluvium, and is the same type of hair loss that your read about above in the Traumatic Events section. The hair loss typically starts around two to three months after the illness, and will rarely occur at the time of being sick. Assuming you recover from your illness, you should expect the hair loss to be temporary and resolve by itself.

Although less common, some illnesses can directly cause a loss of hair at the time of being sick. Some examples include thyroid disease, alopecia areata, and certain types of infection. Due to the number of different types of illnesses that can directly cause hair loss, we cannot list them all out but we advise you to work with your doctor to determine if any illnesses you are suffering from may be associated with hair loss.

6. Medication
 

Some medication may cause hair loss as a side effect. People respond differently to the same medication, and so not everyone may experience hair loss or the other listed side effects. There are two types of drug-induced hair loss: telogen effluvium and anagen effluvium.

Most medications which cause hair loss are related to telogen effluvium. This is the same type of hair loss that you read about above in the Traumatic Events section. This type of hair loss is typically short-term, and will occur around two to three months after you start taking the medication. The hair loss is almost always temporary, and your hair will grow back once you no longer need to take the medication. This type of hair loss is sometimes more difficult to identify, and you will have to think back two to three months to identify any new medications you started taking which may be causing your hair loss.

Anagen effluvium is most often associated with people taking chemotherapy drugs. In the process of destroying cancer cells, these drugs also attack and destroy the roots of your hair. You may experience hair loss across your body. Although this type of hair loss is more severe, hair usually grows back after you have stopped chemotherapy treatment.

7. Hairstyles and products
 

Hair Iron

Some hairstyles can actually cause hair loss in women. If you pull your hair back in very tight hairstyles, such as having tight braids or a tight ponytail, your hair around your hairline may fall out over time. Doing it every now and again won't have a significant affect, but doing it every day will unfortunately damage your hairline over time. The scientific term for this type of hair loss is traction alopecia. It causes damage to your hair follicles and is may be accompanied by redness, an uneven hairline, and in the worst cases there may be visible scarring. The solution is to avoid pulling back your hair into very tight hairstyles, and if you really feel the need to, make sure you don't do it every day.


Another cause of hair loss related to hairstyling is heat damage. All those times you use a hot hairdryer, hair straighteners, curling iron and other forms of heat styling, you might be causing permanent damage to your hair. Your hair may begin to break off easily, cause split ends, or cause the hair strands to become more porous. The only solution is to avoid heat styling every day, avoid direct heat to the scalp, ensure you use heat protection products , and keep the temperature setting on styling appliances low.


Certain hair products can also cause your hair to fall out. Lots of shampoos contain harmful ingredients such as sulfates and parabens, which can be found in many mainstream brands. If you use these types of shampoos, you may be causing your hair loss over time. A milder shampoo will not only clean the scalp but will help to maintain natural moisture without over stripping. We have listed out all the harmful ingredients you should avoid and how to spot a good shampoo for your hair in the following article. You can find out more about hair loss related to styling and heat application here.

Conclusion

As you can see, there are many different reasons why your hair might be falling out. We have outlined the most common causes in the above article. Identifying the right cause will help you find the right treatment to stop hair loss . We've gone into much further detail throughout this website  on the above causes and more, so have a browse or use the search bar to find more information. We've also put together practical solutions and hair advice you can try to promote healthy hair.


Take a look at our recommended reading list. The more you read, the more likely you are to identify the cause of your hair loss.

References

Please click below if you want to read the science behind this article.

Recommended for you

Thin hair and scalp and broken hair

Read more about female pattern baldness, which is hair loss caused by your genetics.

Young woman with hair loss problem receiving injection, close up.jpg

Read more about PRP (platelet rich plasma) treatment for hair loss.

Stress and hair loss

Read more about high levels of stress and the negative impact it can have on your hair.