What Causes Hair Shedding and Growth?

When you think of hair, you probably think of style, but that’s not the reason why we have it. The hair on our heads protects the scalp from harmful ultraviolet rays and helps regulate body temperature. Lashes protect our eyes from the sun and particles that can irritate them.

Many of us take our hair and eyelashes for granted—until we start to lose them. Losing hair can be stressful and confusing, but science is helping us understand why it sheds, why it falls out, and why sometimes it doesn’t grow back. As researchers continue to study this phenomenon, they’re able to create better tools and products to help us take care of the hair we have.

What’s the Difference Between Losing Hair and Shedding It?

The human body is in a continuous state of renewal throughout life. Our skin, blood, brain, lungs, stomach, and more turn over around 330 billion cells per day.

In addition, did you know that you shed 100 to 150 hairs on your head every day and one to five eyelashes as part of your body’s renewal cycle?  The good news is that the lashes and hair you shed are replaced by new ones in those follicles, and the cycle starts all over again. Finding hairs on your pillow, in your sink, on your sweater, or left behind in the shower are all normal signs of shedding. You will naturally shed as you wash, brush, comb, and style your hair.

Hair loss, on the other hand, is when hair falls out and doesn’t grow back.

What Causes Hair Loss and Shedding?

There are several potential causes for hair loss, but causes related to heredity are the most common. 

Androgenetic alopecia – also called male or female pattern baldness, is a hereditary condition that can result in permanent hair loss. Women tend to get thinning hair on the top of their heads without a receding hairline, while men tend to develop a receding hairline and thinning on the crown of their heads. 

Alopecia areata – is another form of hereditary hair loss that’s an autoimmune disease. For those with this condition, the immune system attacks the body’s hair follicles. The disease may cause hair to fall out in circular, coin-sized patches.

Anagen effluvium – is a type of temporary hair loss that is a common side effect of chemotherapy drugs and keeps cells from producing new hair. Similarly, radiation used to eradicate brain tumors may cause hair loss and scarring. Once scar tissue forms over the hair follicles, hair will no longer grow there.

Traction alopecia – is hair loss caused by excessive hair styling and intense treatments, particularly hairstyles that pull the hair taut like ponytails, tight braids, and cornrows.

Certain medical conditions – such as scalp infections, can cause hair loss. So can the inability to resist pulling out eyelashes and hairs on the head and elsewhere, a mental health disorder called trichotillomania.

Certain medications – may cause a type of hair loss known as telogen effluvium, which causes hair to fall out prematurely. Medications that treat depression, arthritis, high blood pressure, and arthritis may be to blame. Other potential causes of telogen effluvium include sudden, significant, and intentional weight loss. In addition, a diet deficient in iron, vitamin D, or zinc can lead to telogen effluvium.

You can also experience temporary periods of excessive hair shedding after childbirth, illness with fever, stress, surgeries, and stopping certain medications like prednisone or the birth control pill. For most people, the amount of hair shed will return to normal after six to nine months.  

As far as shedding of your lashes goes, there are a few additional things to keep in mind. Using eyelash curlers, wearing false lashes, having an allergic reaction to eye makeup, or not removing eye makeup can lead to excessive eyelash shedding. Eyelid inflammation, a condition called “blepharitis,” can also contribute to increased lash loss.

What Steps Can I Take to Reduce Shedding?

There are several things you can do to prevent your lashes from shedding. Thoroughly cleaning your eyelids when you wash your face may help reduce lash loss. Avoid using any eye shadow, mascara, or eyeliner you’re allergic to, and completely remove all eye makeup at the end of every day. When you can, try to go without eye makeup to give your lids a rest. If you want to wear false lashes, it could help to use a magnetic version to avoid the need to apply glue. And do your best to leave the lash curlers in the drawer.

If you suffer from blepharitis, use a warm compress to soothe inflammation, and artificial tears to help with dry eyes. There is also some evidence that increasing Omega 3 fats in your diet —either by eating fatty fish like salmon, cod, mackerel, and tuna or by taking a fish oil supplement—may help.

To reduce excessive shedding of the hair on your head, try to avoid hot showers and use cooler settings on the hair dryer. Take some days off from using those hot styling tools like a curling iron or straightener. And wear your hair loose, rather than pulling it up in a ponytail, braid, or bun.

What Causes Hair Growth?

Now that we’ve covered the potential causes behind shedding, let’s look at what it takes for your hair to regrow. To understand what might help hair grow, you need to understand the anatomy of hair. Hair grows when new cells are formed at the base of the root. There are four stages of hair growth. The growth phase (anagen) lasts from two to six years, during which cells are dividing. It’s followed by a transition phase (catagen) of two to three weeks, during which cell division stops. Hair then goes into a resting phase (telogen) of about three months. The final stage (exogen) is when hair sheds.

What Steps Can I Take to Stimulate Hair Growth?

One way to increase hair and lash growth is through dietary changes to make sure you’re getting enough protein and iron—this ensures the cells that are busy multiplying to form hair have everything they need to do the job. Using hair loss treatments may also spur growth of scalp hair, but results vary. There are also lash serums containing prostaglandins that encourage thicker, stronger lashes. To learn more, talk to an online healthcare provider about the options available to stimulate the growth of hair on your head and eyelashes. Combined with dietary changes, stress reduction, and some updates to your beauty routine, these formulas may lead to healthier, fuller hair and lashes.