Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 8/7/2021
Just like a tree grows out of a dense network of roots, each hair on your head grows from a hair follicle that’s hidden beneath the surface of your skin.
Hair follicles play a key role in producing new hairs and allowing them to grow to their full length, density and thickness. More than anything else, a full, healthy head of hair requires healthy and well-cared-for hair follicles.
From male pattern baldness to common bacterial and fungal infections, a wide variety of factors can harm your hair follicles and potentially cause follicular damage.
In some cases, this damage can permanently affect your hair follicles and stop them from growing new hairs.
Below, we’ve explained how hair follicle damage can occur, as well as the effect that it can have on your hairline.
We’ve also covered what you can do to protect and repair your hair follicles for thicker, healthier and better-looking hair.
Hair follicles are small, tunnel-like holes inside your skin from which hair grows. They’re located in many parts of your body, from your scalp and face to your neck, torso, arms and legs.
Follicles vary in size and depth. The hair follicles on your scalp, which grow long, terminal hairs, extend deep into the lower layers of your skin. Other hair follicles, which produce thinner vellus hairs, only extend a smaller distance into your skin.
Your scalp contains approximately 100,000 hair follicles. Each of these follicles produces hairs as part of a multi-stage hair growth cycle, throughout which each hair develops from the bulb of the follicle and grows to its full length.
Since your hair follicles play such a key role in the hair growth process, anything that damages them can have a serious impact on the health and appearance of your hair.
Damage to hair follicles can affect your hair’s growth and cause issues such as hair loss. If your hair follicles are damaged, you may notice the following symptoms:
Hair loss. For most people, the most obvious sign of hair follicle damage is hair loss. As your follicles become damaged, they may stop growing new hairs, resulting in a receding hairline, bald spot at your crown (the area at the top of your head) or diffuse thinning.
Irritated skin. While not always a sign of follicle damage, some conditions that damage your hair follicles may cause your skin to become irritated, itchy and/or uncomfortable.
Several different issues can affect your hair follicles, from hormonal and genetic conditions such as male pattern baldness to infections, inflammatory conditions and even physical damage from certain styling products, hairstyles or treatments.
Male pattern baldness, or androgenetic alopecia, is a form of hair loss caused by a mix of genetic factors and the effects of an androgen hormone called dihydrotestosterone, or DHT.
Your body creates DHT as a byproduct of testosterone. Over time, DHT can bind to receptors in your scalp and, if you’re predisposed to male pattern baldness, cause your hair follicles to shrink and stop producing new hairs.
The classic signs of hair loss from DHT are a receding hairline, visible hair thinning around your crown and excessive hair shedding.
Hair follicle damage from DHT is largely irreversible, meaning it’s important to act quickly if you start to experience this form of hair loss.
We’ve discussed the effects of this hormone on your hair in more detail in our full guide to DHT and male pattern baldness.
Traction alopecia is a form of hair loss. It’s caused by follicular damage that occurs when your hair is pulled repeatedly, either by an overly tight hairstyle or by styling products that pull on the roots of your hair.
Hairstyles that can lead to traction alopecia include dreadlocks, cornrows and other styles that constantly apply tension to your hair follicles.
Over time, this prolonged tension can loosen the hair from the follicle, cause inflammation and result in the growth of scar tissue.
Traction alopecia can affect people from all ethnic groups and backgrounds, although it’s most common in African Americans.
Our guide to traction alopecia treatments provides more information about this form of follicular damage and its effects on your hair.
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Fungal infections such as tinea capitis (scalp ringworm, or scalp fungus) can penetrate into your hair follicles and affect your hair’s ability to grow.
When mild, fungal scalp infections can cause temporary hair shedding. However, when this type of infection becomes severe and causes your skin to become inflamed, it can lead to permanent scarring and hair loss.
Fungal scalp infections are most common in children and teenagers, but they can affect people of all ages and backgrounds.
Because fungal infections can lead to permanent hair follicle damage, it’s important to treat this type of infection as quickly as possible after you notice symptoms.
Folliculitis is an infection that develops in your hair follicles. It looks similar to pimples and can affect hair follicles anywhere on your body, including on your scalp and face.
Many cases of folliculitis are caused by the Staphylococcus bacteria, which can enter into your hair follicles when they’re damaged. Viruses or fungi may cause others.
Common factors that can lead to folliculitis include using a hot tub (especially one that has not been properly maintained), wearing tight sports clothing, shaving or waxing your hair, or using certain types of medication.
Most of the time, folliculitis is a temporary problem that gets better on its own. However, severe forms of folliculitis, such as folliculitis decalvans, can potentially cause scarring and permanent hair loss.
Numerous other conditions can cause cicatricial alopecia — a form of permanent hair loss caused by damage to your hair follicles.
These include inflammatory conditions such as lichen planus, alopecia mucinosa, discoid lupus erythematosus and acne keloidalis.
Other conditions may temporarily affect your hair follicles. For example, telogen effluvium is a form of hair loss that can occur as a result of chronic stress, illness, surgery, nutritional issues, trauma and certain types of medication.
While telogen effluvium may cause your hair follicles to shed hair prematurely, it isn’t known to cause long-term follicular damage.
Because so many issues can have an impact on your hair follicles, it’s important to talk to your healthcare provider if you notice any potential signs of follicular damage.
When it comes to protecting your hair follicles from damage, it’s important to act quickly. This is because long-term exposure to damaging hormones or inflammation can permanently damage your hair follicles and, in some cases, prevent them from growing new hairs.
Put simply, the longer you wait to treat hair follicle damage, the harder it becomes to reverse its effects and protect your hair.
Since damage to hair follicles can occur for a variety of reasons, there’s no one-size-fits-all form of treatment that can protect your hair against all damage.
However, the following techniques can help shield your hair from most follicular damage and help you sustain healthy hair growth.
Finasteride is a medication for male pattern baldness. It works by preventing the conversion of testosterone into DHT. This lowers DHT levels throughout your body and protects your follicles from the DHT-related damage that causes hair loss.
If you’re starting to develop a receding hairline, bald patch or other early signs of male pattern baldness, finasteride is a very effective treatment that you can use to prevent further damage and stop your hair loss.
Since finasteride only protects against DHT, it isn’t effective for fungal infections or other conditions that cause scarring hair loss.
Our guide to finasteride results covers more about how finasteride works, as well as what you can expect after you start using this medication.
You can access finasteride online, following a consultation with a healthcare provider who will determine if a prescription is appropriate.
Minoxidil is a topical medication that stimulates hair growth. It works by moving hairs into the anagen, or growth, phase of the hair growth cycle and increasing blood flow to your scalp.
While minoxidil doesn’t appear to treat damaged hair follicles, it can improve hair growth and give your hair a thicker, denser appearance. Research shows that it’s particularly effective at promoting hair growth when it’s used with finasteride.
Hims offer minoxidil online, either as minoxidil liquid or minoxidil foam, or with other proven hair growth products in our Hair Power Pack.
If you wear your hair in cornrows, dreadlocks, a man bun or slicked back across your scalp, it’s possible that your hairstyle is damaging your hair follicles.
To ease pressure on your hair follicles, try switching to a hairstyle that puts less stress on the roots of your hair. Avoid strong hold gels, waxes and other styling products, as these may tug on your hair and contribute to damage.
Fungal infections, such as ringworm, jock itch and athlete’s foot, can potentially spread to your scalp when they’re left untreated.
If you notice any of the signs of a fungal infection, it’s essential to treat it as early as possible, especially if your scalp is already affected.
Topical medication is used to treat most fungal infections. When an infection is severe or doesn’t respond to topical treatments, you may need to talk to your healthcare provider about using oral antifungal medication.
For tinea capitis, you’ll typically need to use an oral antifungal medication such as griseofulvin, itraconazole or fluconazole for several weeks to clear the infection.
Your healthcare provider may also recommend using an antifungal shampoo to stop the fungal infection from spreading elsewhere on your body.
Make sure to finish your entire course of medication, even if your symptoms improve during the first few weeks. This will help prevent the infection from coming back.
Regularly washing your hair isn’t just important for your hair’s look, smell and texture. It also helps keep your scalp and hair follicles healthy by preventing the scalp buildup of sebum, germs, dead skin cells and other unwanted substances.
The American Academy of Dermatology recommends washing your hair based on the amount of oil your scalp produces.
If you have an oily scalp, you may need to wash your hair on a daily basis. If your scalp is dry, or if you have chemically treated hair that dries out easily, you may benefit from washing your hair every few days.
To keep your scalp and hair in optimal condition, choose a shampoo that’s formulated for hair growth, such as our Hair Thickening Shampoo.
Currently, there isn’t any scientific evidence to show that your diet plays a role in male pattern baldness or issues like folliculitis.
However, eating a balanced diet can help supply your hair follicles with the essential nutrients required for healthy hair growth.
Our guide to the best foods for hair growth lists foods to prioritize, including eggs, fish that’s rich in omega-3 fatty acids, avocados, leafy greens, nuts and lean cuts of red meat.
Some hair growth supplements, such as our Biotin Gummy Vitamins, can also help give your body the nutrients it needs to support optimal hair follicle function.
Certain habits, such as smoking or not getting enough sleep, may affect hair growth and prevent your hair follicles from producing thick, healthy hair.
For example, research shows a connection between smoking and several different forms of hair loss, including male pattern baldness and frontal fibrosing alopecia, or scarring hair loss.
In addition to eating a healthy, balanced diet, try to maintain a healthy lifestyle to keep your hair in optimal condition. This could mean getting at least seven hours of sleep, limiting your alcohol consumption(Does alcohol cause hair loss?) or making efforts to quit smoking.
These lifestyle changes not only help improve your hair health — they also offer other benefits for your overall health and wellbeing.
Several different issues can damage your hair follicles, including male pattern baldness and skin conditions such as tinea capitis and folliculitis.
When it comes to repairing hair follicle damage, it’s important to act as quickly as possible. Take action as soon as you spot the signs of follicular damage and you’ll put yourself in the strongest position to protect and restore your hair.
Our range of hair loss treatments includes several science-based medications that can treat and prevent follicular damage, including finasteride and minoxidil.
You can learn more about growing healthy, thick hair in our full guide to the most effective ways to increase hair growth.