The hair growth cycle is the process in which your hair grows, transitions, and rests in three stages: anagen, catagen, and telogen. These stages of the hair growth cycle determine how your hair develops and sheds. Here’s an interesting fact: Did you know that humans generally have about 100,000 to 150,000 hairs growing out of their scalp? In this article, we will explore each of these stages in more detail to give you a better understanding of the hair growth cycle stages, why we lose hair, and how hair growth is regulated. 

The hair on your head is not in a constant stage of growth. Although the anagen, or growth stage, can last for several years, there are periods of rest during which no growth occurs, followed by shedding. While it can be alarming to lose hair, it is important to remember that losing up to 150 strands per day is completely normal.

In most healthy adults, we quickly make up the lost hair during the next growth phase. There are, however, a few factors that could affect hair growth or could increase hair loss. You will also get a better understanding of these factors in this article. 

What is the hair growth cycle?

The four stages of the hair growth cycle are:

• Anagen
• Catagen 
• Telogen
• Exogen

Now let’s look at each of these in more detail.

Anagen - the growth stage

This is the stage in which hair is actively growing. The anagen stage can range from 2 to 8 years and is typically the longest of the four stages. About 90% of your hair is in the anagen stage at any given time. During this phase, your hair can grow by at least a centimetre each month. The rate of growth depends on various factors, such as age, genetics, health, and nutrition. During this stage, hair follicles actively push hair out of the scalp and will continue to do so until the next stage. The hair follicle is a cylindrical-shaped structure located in the dermal and epidermal layers of your scalp. 

Within the follicle, the hair root is connected to blood vessels and receives a constant supply of nutrients for healthy growth. The ultimate length of your hair will, of course, depend on how long you let it grow or if you choose to keep it short. This stage of the hair growth cycle eventually pauses to give way for the next stage. A few changes occur during the next two stages of the hair growth cycle.

Catagen - the transition stage

The second stage in the hair growth cycle is the catagen or transition stage. During this stage, the hair root detaches from the blood supply and stops growing. In the catagen stage, your hair will remain at the same length for about 2-3 weeks before entering the next stage of the cycle. Only up to 3% of your hair goes through this stage at a time. The follicle also starts to shrink during the catagen stage. After this, hair transitions into the next two stages of the hair growth cycle.

Telogen - the resting stage

The third stage in the cycle is the telogen stage. This stage is similar to the catagen stage, but with a few differences. During the catagen stage, the hair root detaches from the blood supply. In the telogen stage, the root starts to shrink and forms a club shape. This is why hair in this stage is also called club hair. The telogen, or resting, stage can last for 2-3 months, during which the papilla, the area within the follicle containing the blood vessels, rests and prepares to restart the cycle. 

The root gets more distant from the base of the follicle, which provides space for a new strand of hair to start growing. Almost 10% of your hair is in this stage at any given time. This is the stage when your hair can most easily be detached from the scalp. This is typically the hair you see in your comb or brush after use, or the hair that gets washed away after you shampoo. As you can see, it is completely normal for some amount of hair to be lost at this time, and there is nothing to worry about.

Exogen - the shedding stage

During the hair growth cycle, the exogen (shedding) stage separates the hair from the follicle. You can shed about 100-150 hairs every day as part of the hair cycle. This hair detaches because a new hair is growing within the follicle and needs to push out the mature hair to make room for itself. So, if the older hair didn’t fall off, there would be no place for new hair to take its place. 

The exogen or shedding stage lasts a few months, which is why you experience some amount of hair loss throughout the year. As most of your hair is in the anagen stage, you don’t notice the growth of new hair that is slowly replacing the existing hair. As long as the hair growth cycle is actively taking place, you will continue to have healthy hair that grows well.

Factors that affect hair growth regulation

Now that you have understood the stages of the hair growth cycle, we can take a closer look at the factors that either aid or disrupt it.

Age

As you have probably guessed, hair grows faster in children. While our bodies are actively growing, the anagen stage also lasts longer—the hair growth rate and anagen duration decrease with age. Hair quality also starts to change as the follicles age. However, there are ways to keep your hair healthy for longer. 

Genetics

Our genes play an important role in hair growth. Your genetics primarily determines the texture, colour, thickness, and even rate of growth. If you’ve asked someone the secret to their thick hair, you’ve probably heard the answer, ‘good genes. So if you have been blessed with generous locks, you can thank your family. But also remember to take good care of your hair to maintain its natural beauty.

Nutrition

Hair is made up of protein and requires adequate protein in your diet to stay healthy and grow well. Dairy products, eggs, lentils and pulses are a few of the foods you can include in your diet to ensure that you get enough protein. Besides protein, vitamins and minerals such as vitamins A, B7, C, D, and E, as well as iron and zinc, are also essential for healthy hair growth. Omega-3 fatty acids are another type of nutrient that promotes healthy hair. If you feel your diet is lacking in any way, you can also include Traya’s hair growth supplement to ensure you are getting all the nutrition you need. 

Stress

Stress is often an invisible but important factor in hair health. As stress disrupts nutrient absorption, blood supply, hormone regulation and so on, it can adversely affect the hair growth cycle. If you have been losing more hair than usual, you might want to check your stress levels, especially if you are otherwise healthy and eating well. Stress management techniques such as meditation, deep breathing, and yoga can help maintain overall health and promote hair growth.

Hormones

Hormones help to maintain balance in the body. Irregularities in hormone levels can lead to hair loss or slower hair growth. Conditions like hypothyroidism, perimenopause and menopause, and hypertension affect hormonal balance and, in turn, could disrupt the hair growth cycle. If you are experiencing any of these conditions, you can talk to your doctor about managing your hormones to improve your health and well-being.

Illness and medication

Certain illnesses can also cause hair loss. In most cases, this happens because the body is fighting an infection and diverting resources, such as nutrients and blood supply, to the immune system. Generally, the hair growth cycle returns to normal after you have recovered from the illness. Some medications can also cause hair loss as a side effect. This type of hair loss is usually also resolved once you have stopped the medication and your body has returned to normal function. 

Scalp infections and autoimmune disease

These conditions specifically affect the scalp and the hair follicles. Scalp fungal infections that cause dandruff can cause hair loss. Autoimmune diseases like alopecia, in which the body’s immune system attacks the hair follicles, are another cause of hair loss. Your doctor will be able to prescribe the right treatment for you to help you overcome these conditions.

A healthy diet and lifestyle play a big role in maintaining healthy hair. While some illnesses and medications can affect hair growth, the right treatment can help restore healthy hair.

Frequently Asked Questions

1. Can I make my hair grow faster?

Your age, genetics and overall health determine the rate at which your hair grows. While you can ensure that you are consuming a healthy diet and providing the right nutrition for your hair, you can’t actually make your hair grow faster than its normal rate.

2. Does insomnia affect hair growth?

Yes, insomnia can affect hair growth. While we sleep, our bodies repair and replace damaged cells, including those in hair follicles. Insomnia-induced sleep deprivation can disrupt this process and weaken the hair follicles. This is why it is important to get sufficient, high-quality sleep to ensure you have healthy hair.

3. Why is my hair thinning?

There can be several reasons why your hair is thinning, including stress, hormonal changes, illness and medication. Women who are going through perimenopause and menopause might experience hair loss and thinning due to a drop in estrogen levels. The male equivalent of hair thinning is a receding hairline and male pattern baldness.

4. Will a hair supplement improve hair growth?

Hair supplements ensure that you are getting all the required nutrients for healthy hair growth. If you are experiencing hair loss due to a nutrient deficiency, then hair growth supplements can be very helpful. Also, make sure to follow a good diet rich in protein, vitamins and minerals.

5. Does frequent trimming of my hair increase hair growth?

While frequent hair trimming can make your hair look fuller and healthier by removing split and damaged ends, it does not actually increase hair growth. The health of the hair follicles and several other factors, such as a good diet and lifestyle, determine hair growth.

6. Does wearing a cap/hat often cause hair loss?

Wearing loose caps or hats should not cause hair loss. However, tight headgear worn for extended periods can affect your scalp. Remaining in a cap or hat that is damp with sweat can cause scalp infections, which may lead to hair loss.

7. Will I lose hair if I always tie it in a ponytail? 

If you always wear your hair in a tight ponytail that pulls at your hair roots, you can develop a condition called traction alopecia, which can result in hair loss.

References:

1. https://www.ncbi.nlm.nih.gov/books/NBK499948/
2. https://pmc.ncbi.nlm.nih.gov/articles/PMC9917549/ 
3. https://ishrs.org/media/faq/

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