Medically reviewed by Vicky Davis, FNP
Written by Our Editorial Team
Last updated 9/17/2021
Seeing too many strands in the shower?
A bit of hair shedding is normal. In fact, on average, a person loses between 50 and 100 hairs per day.
However, if you start noticing your head of hair looking especially thin, it can be concerning.
But hair doesn’t just start to thin for no good reason. Generally, if you notice this happening, there’s a cause.
From heredity to stress, there are a number of factors that can cause your hair to thin. These include:
There are some women who notice their hair starting to thin in their teens, though it’s more common later in life.
It's likely that you have a family history of hair thinning and loss if you are experiencing this.
Most women who have genetic hair loss first notice overall thinning. Sometimes the hair loss can also manifest as a widening part.
So, what causes this type of hair loss? It happens when your body has an excessive response to androgens. Androgens are the hormones that promote hair growth and reproductive abilities.
Curious about the relation between hair growth rate and age? You can read about it in our guide.
Testosterone is usually most connected with men. But this hormone is also in women. Testosterone promotes reproductive and non-reproductive functions in females.
But testosterone can create problems for hair. When it roams free, it can attach to androgen receptors in the hair bulb and the dermal papilla which regulates hair growth.
This may shrink your hair follicles.
That roaming testosterone may also be converted into dihydrotestosterone (DHT), which can then attach to androgen receptors and cause hair loss.
Emotional stress can be a physical doozy, and can take a toll on your hair and lead to hair loss and thinning. When this happens, it is called telogen effluvium.
Telogen effluvium usually presents as sudden thinning around your entire scalp. Thankfully, this type of hair loss is not permanent.
When this type of hair thinning occurs, it’s forcing hairs into the telogen phase, which is the final phase of your hair’s growth cycle.
This can cause your hairs to fall out without replacement hairs growing in to replace them.
Generally, you’ll notice hair thinning a few months after a stressful life event occurs.
When you have less of them, there’s more room for testosterone to roam free — which can lead to hair loss and thinning.
Your thyroid gland impacts the health of your hair follicles.
Hypothyroidism (when your body produces too little of the thyroid hormone) and hyperthyroidism (when you produce too much of the thyroid hormone) can affect hair growth.
Hypothyroidism can cause delays in hair growth, which means you may lose hair without it replacing itself. Because of this, your hair will appear thinner.
Hyperthyroidism can cause finer hair to grow, which is more likely to break. This can also give the appearance of less hair overall.
Coloring, relaxing and otherwise chemically treating your hair can all cause damage to your strands. You may notice gradual or sudden hair loss from these types of treatments.
This is especially true if you do these things frequently. And too much damage can lead to hair thinning.
Tight hairstyles like a ponytail or bun can also be problematic and cause loss of hair. When this happens, it’s called traction alopecia. Essentially, the constant pulling can lead to permanent hair loss.
Good news: There are treatment options available to help you handle hair thinning. Here are some of the most common options:
Minoxidil is sold under the brand name Rogaine® and comes in a 2% solution or 5% foam. It is also FDA-approved for androgenetic alopecia.
When applied, minoxidil sends a signal to your blood vessels to open wide so that more nutrients and oxygen can get to the hair to improve its health.
It also stretches out the growth period for hair, which means more follicles are created to replace lost hair.
The acne drug spironolactone is also sometimes prescribed — especially if you’re dealing with genetic hair loss.
Spironolactone prevents testosterone from turning into DHT.
It also slows down the production of androgens, which will prevent or slow hair loss.
Before taking any type of medication, be sure to tell your healthcare professional about any health conditions you may have.
Your hair may need some TLC. These tips can help turn around hair thinning:
Allow your hair to air dry. And when you do use hair tools, set them on the lowest setting to avoid burning strands.
Avoid tight ponytails and buns and choose looser styles.
If you color your hair, add more time between touch-ups and avoid doing multiple chemical services (like coloring, relaxing or perming) at once. Instead, wait two weeks between each service.
From hereditary hair loss, lifestyle habits to mental health issues, there are a number of reasons hair thinning or loss in women occurs.
The best way to assess what’s going on and why your scalp hair is thinning is to see a healthcare professional.
They should be able to discuss your scalp and you figure out why you may be experiencing hair thinning.
After you figure out why your hair is thinning, you’ll be able to work with a healthcare professional to figure out what hair loss treatments could work for you.
When you do this, it's only a matter of time before you hopefully notice some healthy hair growth.