Thinning of hair is an early manifestation of hair loss and may herald extensive baldness. Hair loss is one of the most common cosmetic conditions affecting adult men and women.
It is estimated that up to 85% of men experience some degree of hair loss as they pass the age of 50 years. Though less common in women, some evidence of hair loss is present in approximately half of them by the same age.
Early intervention in the form of preventive measures, medications, and other hair restoration options may halt the progression of hair thinning to obvious balding. In this article, we will discuss the causes, symptoms, and treatment options for hair thinning.
What is thinning hair?
Normally, humans have 80 thousand to 120 thousand hairs on their heads, with an average hair density of 148 to 172 per cm2, depending on the ethnicity and area of the scalp. A decreased hair density from the normal state in an individual is thinning of the hair.
The vertex usually has the highest hair density. Some hair loss is part of the natural hair growth cycle. According to the American Academy of Dermatology, loss of 50-100 hair per day is normal. As the old hairs shed, young ones sprout from the existing hair follicles. However, when the loss of hair is more than what is considered routine, noticeable hair thinning and eventually, bald patches start appearing on the scalp.
The biggest enemy of men’s hair is their hormone, dihydrotestosterone. This hormone is responsible for hair thinning in more than half of men above the age of 30 years, a condition called androgenetic alopecia or male pattern baldness. When hair is lost in male pattern baldness, the most obvious effect is the receding hairline, though hair thinning at other areas, especially the vertex is also present. In hair thinning, not only is there a reduction in the quantity of hair but the volume and thickness of individual hair strands shrink too. Moreover, in the early stages, villous hairs replace the lost terminal hair which is thin and tapered towards the ends.
Female pattern baldness affects about 50 percent of women by the time they reach fifty years of age. In contrast to androgenetic alopecia in men, receding hairline is not a common feature, at least in the early stages. There is diffuse hair thinning. Widening of the part is a good indicator of hair loss. Receding hairline with thinning hair is more common in other conditions like frontal fibrosing alopecia. Some Immune diseases like Lupus (SLE) are more common in women and hair thinning is one of their common features.
When does thinning hair occur?
Thinning hair is observed in all conditions, but is more common in adults, and the incidence increases with age. In young children, fungal infections of the scalp can cause thinning hair which is confined to the infected area. Traction alopecia is seen in many young girls, especially of African descent, due to traumatic hairstyles. In adult men, the effects of androgenetic alopecia are present in 80% by the age of 50 years. Noticeably thinned hair may be noted as early as the late teens or early twenties. Hair thinning in women is apparent in half of them by the age of 50 years. Hairline thinning due to fibrosing alopecia mostly affects post-menopausal women.
Hair thinning results from mild to moderate hair loss. In the initial stages, there may not be noticeable changes. In the later stages, the hair appears sparser. The final stage is obvious baldness.
Increased hair shedding: As hairs grow older, they are shed and new ones take their place. This is the normal hair cycle and the shed hair is routinely observed while combing and in the shower. When the hair sheds at a pace that can’t be replaced or the follicles are permanently damaged, pathologic hair thinning results. The hair pull test is an easy method to diagnose hair loss. The doctor grabs and gently tugs on strands of hair in a small scalp area. If six or more hairs fall out, it strongly suggests active hair loss.
Scalp changes: Scarring, itching, scaling, etc. are some of the changes that may be noticed in a few cases on the areas where hair is lost.Not all cases have these symptoms though. In patients with androgenetic alopecia, there are usually no scalp changes. Scarring may be noticed in inflammatory conditions like frontal fibrosing alopecia. Itching and scaling may be present if there is an active fungal infection of the scalp.
Changes in the hair strands: In thinning hair, the volume of the individual hair strand is reduced. The hair is short and especially thinner towards the ends.
Bald spots: The pattern of balding depends on the underlying cause. In androgenetic alopecia, widening of the part is a commonly noticed early symptom in women. In men, there is frontotemporal hairline recession and hair thinning at the vertex. In alopecia areata, there are discrete bald patches on the scalp, while hair density in the remaining areas is normal. In telogen effluvium, there is diffuse hair thinning over a short period. The cause is usually a stressful condition like severe illness.
The severity of hair thinning is graded differently between men and women and based on the underlying disorder since the pattern of hair loss is different.
In Men: The stages of hair loss in male-pattern baldness are described by the Norwood scale. It has 7 stages, starting from minimal hair thinning and gradually increasing in severity to Norwood VII, which defines complete baldness. In Norwood I, the hair loss may not be noticeable. In Norwood II there is thinning of hair in the temporal areas. In Norwood II and III, the frontotemporal hairline recession progresses with thinning hair at the vertex. The receding hairline reaches the midline of the scalp by Norwood IV and almost touches the thinned area at the vertex in Norwood V. Norwood VI and VII are advanced stages of hair loss. A horseshoe-shaped hair-bearing area at the back of the head is all that remains in Norwood VII.
In Women: For female pattern hair loss, the Ludwig scale is an equivalent grading system. It has three grades. In grade 1 there is minimal but perceptible thinning of hair at the vertex, without a receding hairline. In grade 2 the hair thinning is significant. There is widening of the part and the scalp can be seen beneath the sparse hair. Grade 3 is severe hair loss, where large areas of the scalp are affected.
The most common cause of hair thinning, as mentioned above, is patterned baldness. Heredity plays a significant role too, especially in men. And where nature has its say, nurture can’t remain silent for long.
So, lifestyle measures, from hair styling routines and hair grooming practices to occupational risks, are an important cause of hair thinning as well. A number of medical conditions can initiate or accelerate the process of hair loss, from diseases limited to the scalp like fungal infections to multi-system disorders like lupus. We will discuss these factors one by one.
We inherit the color and texture of our hair from our parents. Likewise, the tendency to hair-fall is also, in part, dependent on the genes we carry. For men, there are several genes identified, many of them located on the X-chromosome, whose inheritance determines predisposition to alopecia. Eighty percent of men who have patterned baldness have a history of hair loss in their father. For women, the genetic basis is not well-characterized but a hereditary predisposition to hair loss is probable. The tendency to patterned hair loss is a polygenic trait, with more than 60 genes identified by researchers.
Hair health and growth are not isolated from that of the rest of the body. Hence, lifestyle measures that impact overall health like alcohol, smoking, and lack of physical activity are known to negatively impact hair growth as well and may make them prone to falling. Stress is another factor known to contribute to hair loss. Haircare practices, predictably, play an important role in hair thinning. Unnatural hairstyles, which put too much pull on all or a group of hair strands are known to cause hair thinning – a condition called traction alopecia. Tight ponytails, tight braids, cornrows, and dreadlocks are a few examples of such traumatic hairstyles. Regular shampooing, wearing your hair naturally and general healthy habits are important for healthy hair.
Diseases and infections
Hormonal disorders: Apart from DHT, which causes androgenetic alopecia, hair thinning is often seen in diseases of the thyroid gland. An excess (hyperthyroidism) or lack of (hypothyroidism) thyroid hormone affects multiple systems in the body, including the hair. Disorders of the adrenal gland also affect hair growth.
Inflammatory disorders: Alopecia areata is an autoimmune disorder in which the body’s immune system attacks hair follicles, leading to bald patches on the head and other areas of the body. Thinning hair is a common feature of systemic lupus erythematosus (SLE), or simply lupus, another autoimmune disorder involving multiple body systems.
Other diseases and infections: Fungal scalp infections (tinea capitis) can cause thinning hair which reverses when the infection is treated with antifungal drugs. Telogen effluvium, nutritional deficiencies, and frontal fibrosing alopecia are some of the other causes of thinning hair.
Thinning hair is preventable in many cases. While hereditary predisposition cannot be altered, the adoption of healthy lifestyle measures and diet can go a long way to improve overall hair health.
Early identification of hair loss and prompt treatment can prevent extensive baldness and permanent hair loss. Some such measures that can help prevent hair loss include:
- Diet: Various studies have shown the beneficial effects of the micronutrients vitamins A and D, biotin, zinc, and selenium in promoting hair growth and preventing hair loss. Since keratin (a protein) is the main constituent of hairs, a balanced diet rich in protein is important for the overall health but especially that of the hair. No specific diet has been conclusively shown to be superior for hair loss prevention. However, a recent study 1 found that the use of vegetables and fresh herbs (called the Mediterranean diet) may reduce the risk of androgenetic alopecia. Ginseng and saw palmetto may also promote hair growth. The use of dietary supplements, however, should be done in consultation with a nutritionist or physician.
- Haircare practices: Regular shampooing and proper scalp hygiene are important for adequate hair care. Olive oil or coconut oil may promote hair growth too. Avoid overtreating your hair with chemicals, unapproved dyes, relaxers, or heat. They make the hair brittle, frizzy, and easily breakable. Likewise, traumatic hairstyles, like tight braids, cornrows, etc., damage the hair mechanically. Other harmful practices include prolonged use of headbands and heavy hair extensions. Adopting gentle hairstyles, changing hairstyles frequently, and wearing your hair naturally can reduce the risk of hair thinning.
- Early identification and treatment: An early consultation is useful to identify the underlying cause of hair thinning so that corrective measures can be adopted or treatments like Minoxidil and Finasteride can be initiated.
Treatment of thinning hair or hair loss depends on many factors: the severity of hair loss, the underlying condition causing hair thinning (if any), the availability of sufficient hair to serve as a donor for hair transplant surgery.
In the early stages, medications are usually tried. Platelet-rich plasma (PRP) may be used in cases that don’t respond to medicines. Natural remedies like the use of coconut oil, saw-palmetto, or biotin are often promoted as hair growth products and may have modest benefits.
Drugs used for hair loss: Minoxidil, originally a blood pressure-lowering medicine, is now widely used for the treatment of hair loss. It is available for topical application, either sprayed over the scalp or applied as a foam. The spray-form comes in strengths of 2% or 5% solutions and is used twice daily while the foam is applied once a day. Minoxidil is FDA-approved for the treatment of androgenetic alopecia in both men and women but is also commonly used off-label in other hair loss conditions.
Finasteride is used for the treatment of male-pattern baldness only. It is a prescription medicine and contraindicated in pregnant women. Finasteride blocks the conversion of testosterone to dihydrotestosterone, the hormone responsible for male-pattern baldness. It protects the hair from the effects of DHT, thus reducing hair thinning and promoting the growth of new hair.
Efficacy of medical treatment: Both Minoxidil and Finasteride are effective in androgenetic alopecia, with response rates of 60-80% reported in clinical studies.They are unlikely to be of much help in inflammatory conditions. The main problem with them, however, is that they need to be used indefinitely as the effects wear off quickly when the drugs are stopped.
Other medications: Hair loss due to immune-mediated or inflammatory conditions may be treated with corticosteroids, either topical or oral. Fungal infections will require treatment with anti-fungal medications.
Indications of Hair Transplants:
- Patients with extensive hair loss
- Hair loss unresponsive to medications
Types of hair transplant procedures:
Hair transplants is performed under local anesthesia. Commonly used surgical techniques include follicle unit extraction (FUE), follicle unit transplant (FUT), and direct hair implant (DHI). In FUT, a strip of skin containing hair follicles is cut from the donor area, usually the back of the head, and the follicles are then implanted into the bald area. In FUE, individual follicles rather than a whole strip are harvested. It is the most commonly used hair transplant technique currently. DHI is a modified version of FUE.
A suitable donor area, containing adequate hair follicles, is required from which the follicles can be harvested. Hair at the back of the head is a common donor site since the hair there is resistant to the effects of DHT. The extent of hair loss determines the number of grafts required. For a Norwood type II hair loss, 500-800 grafts may suffice while advanced baldness can require 5000 or more grafts.
Efficacy and outcome:
Hair transplant is generally a safe and effective procedure. Survival rates of more than 90% for the implanted follicles are reported in many studies. The procedure is performed by qualified dermatologists or plastic surgeons. Complete hair restoration after a transplant takes 9-10 months.
Home remedies and other treatments
Scalp micro-pigmentation: It is a non-invasive aesthetic procedure in which dark dots are tattooed as a hair tatto over the areas of the scalp with hair thinning to produce the illusion of a fuller head. It is more suitable for patients with thinning hair than obvious baldness.
Platelet-rich plasma (PRP): PRP is an autologous preparation, with healing and growth-promoting properties. When injected locally, it is effective in the treatment of thinning hair, arthritis, and muscle injuries. For hair loss, PRP is injected below the scalp skin in one or more sessions. It is used either as a standalone treatment option or after a hair transplant to expedite recovery. Early hair loss responds better to PRP than advanced baldness.
Stem cell treatment: Stem cells are collected from adipose tissue, bone marrow, or healthy hair follicles, are transplanted into the areas of hair loss where they transform into hair follicles. They retain the ability to differentiate into many types of specialized body cells when a suitable tissue environment is provided. Stem cell-based therapies have mainly been used in patients with hair thinning due to patterned hair loss.
Home remedies and alternative medicine approaches: Amino acids, biotin, rosemary oil, etc. are some of the popular natural remedies for hair growth. Alternative medicine practices like acupuncture have also been used. Solid scientific evidence for these products and procedures, however, is lacking.