The Causes Of Hair Loss & The Most Common Types Of Alopecia

Many causes can lead to hair loss. Finding out what's causing you to lose hair is the first step to solving these issues. After which, you would know what kind of solutions would best suit you.

In this article, we'll share with you some of the reasons why you're experiencing hair loss.


As much as we like to provide all information, we don't want to get too technical either. You should still consult your doctor to ascertain the cause of your hair loss as we are not medically qualified to give you any advice.

With a population of around 325 million in the United States, a whopping 56 million are suffering from hair loss. Out of which, 35 million are males and 21 million are females. So you can see the extent of this issue.

hair loss causes

For males, by age 35, 40% would have some form of hair loss and by age 85, 80% would have noticeable hair loss.

The Hair Growth Cycle

There are 3 stages of a hair growth cycle: anagen, catagen and telogen.

Here's a video that illustrates the hair growth cycle in a simple way:


The Anagen phase has active hair growth that lasts from 2-7 years. Your hair is in the anagen phase 85-90% of the time. When you're growing older, this stage becomes shorter and thus cause thinner hair over time.

The longer the anagen phase, the longer your hair will grow. The hairs on your arms, eyelashes and legs have a much shorter anagen phase of 30-45 days and that's why they're much shorter than your head hair


At the Catagen phase, this is where transitional hair growth exists which lasts for 2-3 weeks. In this stage, the follicles are detached.


The resting phase of the Telogen stage lasts for 2-3 months. After which, the hair sheds and a new hair is replaced, and so the cycle restarts again. As it is already detached, hair can appear dull and can't be repaired.

What is Alopecia?

Alopecia is just a medical term for hair loss. There are different types of alopecia tagged to various forms of hair loss like androgenetic alopecia, alopecia areata, telogen effluvium, etc.

Who can it affect? Everyone: Men, women, and children.

Common Types of Alopecia

Androgenetic/Androgenic Alopecia (AGA)

AGA is the most common cause of hair loss. It is passed on by your parents, grandparents or relatives. Most call it pattern baldness, and there's a distinction between male pattern baldness (MPB) and female pattern baldness (FPB).

MPB in men has clear patterns. It could start with a receding hairline at the temples resulting in a 'M' shape. Another form is when hair begins to thin at the crown. Both types can lead to partial or complete baldness.

In females, it is different. FPB sufferers don't experience receding hairline but thinning all over the head, but thankfully, complete baldness is rare. Hypothyroidism is also known to be the cause of hair loss in women.

So how does this happen?

Researchers have determined that pattern baldness is caused by a particular androgen called Dihydrotestosterone (DHT).

Increased levels of DHT cause a shorter hair growth cycle which in turn causes shorter and thinner hair strands. Furthermore, the delay in replacing hairs that are shed is increased.

This is the very reason why solutions catered to hair loss are geared towards reducing or blocking the DHT.

Telogen Effluvium (TE)

It is the 2nd most common after AGA but lesser research has been done to understand it further. The condition is harder to define. It simply is the change of the number of hair follicles. During the telogen or resting phase, if the number of these follicles growing hair drops substantially, there is an increase in dormant follicles resulting in hair loss.

Some causes that lead to TE:

  • ​Extreme physical trauma from accidents/surgery
  • Extreme emotional stress
  • Postpartum hair loss after childbirth
  • Thyroid disorders
  • Medications like chemotherapy
  • Diet deficiency

​Alopecia Areata

Alopecia areata happens when the immune system attacks the follicles. You could see round patches on the scalp where the hair falls out. These patches are totally smooth and hairless. Fortunately, the damage is usually not permanent and can regrow in a few months. However, 10% of people may not have the chance for hair regrowth.​

Alopecia universalis and alopecia totalis and both related to areata, just in a more aggressive form.

Alopecia Universalis

Being the most aggressive type of the 3 autoimmune disorders, you may experience loss of all hair including eyelashes and eyebrows.

Alopecia Totalis

It is the loss of all head and facial hair.​

Scarring Alopecia

3% of hair loss patients are suffering from scarring alopecia or cicatricial alopecia. There can be many forms of scarring alopecia but ultimately, it is the permanent destruction of follicles and the formation of scar tissues over the affected area. It is similar to burning a part of your skin which scarring then takes place, allowing no growth of hair to take place anymore.​

Traction Alopecia

It is caused by physical stress (traction). Strong braids, tight ponytails and constant pulling of the hair cause stress on the affected areas and lose hair over time. So make sure to let your hair down and let it take a breather.

What's Next?

It is always important to approach your doctor to find out the real cause of your hair loss.

He or she knows best.

When you're losing hair, there are many psychological effects on your well-being. Don't let these affect you and learn how to cope with them.

You should also check out some solutions available. But before starting any remedies, check with your doctor first.