What Is Hair?
Hair is simple in structure but has essential social functions. Hair consists of a protein called keratin. A hair follicle anchors each hair. The hair bulb forms a hair follicle base. Living cells divide in the hair bulb and grow to form the hair shaft. Blood vessels nourish the hair bulb cells and deliver hormones that alter hair growth and structure at various times of life.
How Does the Hair Growth Cycle Work?
Hair grows at different rates; the average rate is around 1⁄2 inch per month. The hair color is created by the pigment cells in the hair follicle, which produce melanin. The pigment cells die with aging, and the hair turns grey.
There are three stages of the hair growth cycle, from root to hair shedding to actively beginning growth. These are called phase Anagen, phase Catagen, and phase Telogen.
The Anagen Phase
The Anagen phase represents the growth period. The cells in the hair bulb quickly divide, creating new growth of hair. Hair is actively growing from the roots for 2-7 years on average before hair follicles become dormant. Hair may grow anywhere between 18-30 inches during this time. This phase’s length depends on your maximum length of hair, which varies among humans due to genetics, age, health, and many other factors.
The Catagen Phase
The Catagen phase is the second stage of your hair growth cycle. This period is short, and on average, lasts only 2-3 weeks. In this transitional phase, hair stops growing and detaches itself from the blood supply, and is then called a club hair.
The Telogen Phase
Finally, hair enters its third and final phase called the Telogen phase. This phase begins with a period of rest, during which club hairs rest in the root while new hair begins to grow below. This phase will last roughly three months.
What Is Hair Loss?
Hair loss, also known as alopecia or baldness, refers to a loss of head or body hair. The severity of hair loss can differ from small to full body areas. Usually, there is no inflammation or scarring. In some people, hair loss causes psychological distress.
Why Does Hair Fall Out? What Are the Types of Hair Loss?
Hair loss is a disorder caused by an interruption in the hair production cycle in the body. It can occur on the body anywhere but most commonly affects the scalp. Averagely, the scalp has 100,000 hairs that cycle through growing, resting, falling out, and regenerating periods.
If the hair growth cycle is disrupted, or if a hair follicle is damaged, hair may start falling out faster than it is regenerated, leading to symptoms such as a receding hairline, hair falling out in patches or thinning overall.
Hair loss may be linked to genetics, though many medicines and behavior conditions may intervene with the growth cycle and lead to hair loss.
Androgenetic alopecia is the most common type of hair loss in the world. Commonly called male hair loss pattern or female hair loss pattern, androgenetic alopecia is hereditary.
Male Pattern Hair Loss
In men, hair loss can begin after puberty and progress over the years or decades. It begins above the temples and continues around the head’s perimeter and top, often leaving a hair ring along the scalp’s bottom. Many men with hair loss from a male pattern eventually get bald.
Female Pattern Hair Loss
In women, the hair thins slowly all over the scalp, but the hairline usually does not recede. Many women experience hair loss of this type as a natural part of aging. After puberty, though, hair loss may begin at any time. Female hair loss patterns can dramatically make hair thin, but it rarely leads to baldness.
Telogen effluvium, a kind of hair loss, occurs when large numbers of follicles on the scalp enter the hair growth cycle’s resting phase. Even so, the next phase of growth does not start. This causes hair to fall out without new hair growth all over the scalp.
Telogen effluvium generally does not cause complete baldness. You may lose 300 to 500 hairs in a day, however, and hair may appear thin, particularly at the crowns and temples.
A medical event or condition typically causes hair loss in this type. Telogen effluvium may also occur because of a vitamin or mineral deficiency. The starting or stopping of oral contraceptives can also cause hair loss.
Telogen effluvium usually starts three months after a medical outcome. If the triggering event is temporary, your hair may grow back after six months. If the hair loss lasts longer than six months, telogen effluvium is considered chronic. This type of hair loss can last in some people for years, for reasons unclear to doctors.
Anagen effluvium is a rapid loss of hair resulting from medical treatment, like chemotherapy. These potent, fast-acting drugs kill cancer cells. However, they may also shut down the production of scalp hair follicles and other parts of the body. Usually, hair grows back by itself after chemotherapy ends.
Alopecia areata is an autoimmune condition, which means healthy tissues, including hair follicles, are attacked by the body’s immune system. This condition causes hair to fall out and prevents the growth of new hair.
This condition can affect adults and children, and hair loss can start without warning and suddenly. Scalp hair typically falls out in tiny patches and is not painful. Hair may also fall out in other parts of the body, including the eyebrows and eyelashes.
Tinea capitis, also known as scalp ringworm, is a fungal scalp infection that is a common cause of hair loss in children. This condition causes hair to fall out in patches, sometimes circular, leading to bald spots, which may become larger over time.
Cicatricial alopecia, also known as scarring alopecia, is a rare type of hair loss in which inflammation destroys hair follicles and leads to scar tissue formation. Hair does not regrow after shaping scar tissue.
Types of cicatricial alopecia include:
Lichen planopilaris, a kind of alopecia, occurs when the scalp is affected by a common skin condition, called the lichen planus. Lichen planopilaris can cause a dry, flaky rash to appear on the skin, causing hair to fall out in clumps on the scalp. The scalp can also become red, irritated, and covered in small white or red itchy, painful or burning bumps. It affects women more than men.
Discoid Lupus Erythematosus
Discoid lupus erythematosus is a type of lupus cutaneous, an autoimmune disease affecting the skin. It can lead to inflamed ears, face and scalp sores, and scarring. One symptom of the disease is hair loss. When scar tissue is forming on the scalp, hair in that area can no longer grow.
Loss of hair caused by folliculitis decalvans, an inflammatory disorder that causes hair follicles to be destroyed, is often accompanied by redness, swelling, and scalp lesions that may be itchy or contain pus, known as pustules. This type of hair loss is not reversible.
Dissecting Cellulitis of the Scalp
The dissection of the scalp’s cellulite, a rare condition, causes the scalp to form pustules or lumps. This condition can also lead to scar tissue development, destroying hair follicles, and causing hair loss.
Frontal Fibrosing Alopecia
Typically, frontal fibrosing alopecia occurs in a pattern of receding hairline. It can also lead to loss of hair in the eyebrows and underarms. Postmenopausal women most commonly experience frontal fibrosing alopecia. The cause of this hair loss is unknown.
Central Centrifugal Cicatricial Alopecia
Hair products or styling techniques that damage hair follicles might cause central centrifugal cicatricial alopecia. Using hair relaxers, blow dryers, curling iron, and hair extensions can cause central centrifugal cicatricial alopecia, as can a permanent wave or perm process. This condition may also be caused by frequent application of oils, gels, or pomades, which can be reversible if you stop using these hair products or styling techniques.
Hair Shaft Abnormalities
Several types of abnormalities in the hair shaft can lead to hair loss. These conditions make hair strands thin and weaken, making them vulnerable to fracture. The hair loss in the follicle does not occur but from a break somewhere along the hair shaft, which is the visible part of a hair strand. This can result in a thinning overall, as well as many small, brittle hairs.Making simple changes to your hair is styled and treated can reverse some abnormalities in the hair shaft. Others may require medical intervention. Types of hair shaft abnormalities include:
Loose Anagen Syndrome
Loose anagen syndrome, most typically occurring in young children, happens when hair not firmly rooted in the follicle can be easily pulled out. After it has reached an arbitrary maximum length, the hair will fall out most of the time. Children with loose anagen syndrome may not often grow beyond a relatively short length of hair. Most commonly, the condition affects girls with brown or blond hair.
People with trichotillomania pull their hair out and have trouble stopping it. This leads to hair loss on the scalp, or on the body elsewhere. Hair often returns if it stops behavior. However, if the pulling continues for many years, hair loss can be permanent.
Some hairstyles, including tight ponytails and braids, with such force, pull hair away from the scalp that hair strands are damaged and fall out. Traction alopecia may lead to thinning hair or bald spots unless the hairstyle is changed.
Hypotrichosis is a rare genetic condition on the scalp and body where very little hair grows. Babies born with this condition may first have typical hair growth; however, a few months later, their hair falls out and is replaced by sparse hair. Many people with hypotrichosis will be bald by age 25.
Understanding the Male Pattern Hair Loss
The most common type of diffuse thinning of hair is male pattern hair loss, and balding occurs in adult males. It is due to a combination of hormones (androgens) and a predisposition to genetics. The male hair loss pattern is also termed androgenetic alopecia. It is characterized by a receding hairline and loss of hair on the head and front. A similar type of hair loss in women, the loss of female hair pattern, results in thinning hair on the scalp’s mid-frontal area and is generally less severe than in men.
What Causes Male Pattern Balding?
Male pattern hair loss is an inherited condition in some scalp areas caused by a genetically determined sensitivity to dihydrotestosterone (DHT). DHT is thought to shorten the hair cycle phase of growth, or anagen, from a usual 3–6-year duration to weeks or months only. This happens along with follicle miniaturization and progressively produces fewer and finer hairs. DHT production is regulated by an enzyme known as 5-alpha reductase.
A couple of women have male pattern hair loss due to excessive androgens and genetic predisposition. These women also tend to suffer from acne, irregular menstruations, and excessive body and facial hair.
Diagnosis of Male Pattern Baldness
To diagnose male pattern baldness, your doctor will usually examine your scalp to determine if you have lost a significant amount of hair. They might use a densitometer device to view miniaturized hair follicles and look at each hair follicle’s space.
There is usually no need to perform a biopsy to diagnose male pattern baldness. This procedure is generally only necessary to determine if a chemical or other external factor causes your hair loss.
Most doctors classify male pattern baldness using a system called the Norwood scale. This scale features reference diagrams for various hair loss patterns, ranging from a receding hairline to almost complete hair loss.
What Is the Norwood Scale?
The Norwood scale (or Hamilton-Norwood scale) is the leading rating system used to measure male baldness patterns. Men typically lose their hair over many decades in one of several common patterns. The Norwood scale provides images that are easy to reference, indicating different stages of balding.
What Are The 7 Stages of Hair Loss Determined by Norwood Scale?
The Norwood scale has seven stages. Each stage measures the severity and pattern.
The front-parietal regions lack bilateral recessions along the anterior border of the hairline. No marked hair loss or hairline recession is observed.
There is a slight hairline recession around the temples. Hair also gets lost, or sparse, along the scalp’s mid frontal border. Nevertheless, the depth of the area affected is much lower than in the front parietal regions. This is commonly called adult hairline or mature hairline.
The first signs of noticeable balding appear. There is a deep, symmetrical recession in the temples, which is only sparsely covered by hair.
Stage 3: Vertex
The hairline remains at stage 2, although the crown of the scalp (the vertex) is experiencing significant hair loss.
The hairline’s recession is harsher than in stage 2, and the vertex contains scattered hair or no hair. There are deep, usually symmetrical, frontotemporal recessions, and they are either bare or very sparsely covered with hair.
The hair loss areas are more pronounced than in stage 4. They are still divided, but there is a thinner and sparser band of hair between them.
The hair connection that crosses the crown is gone with only the residual sparse hair. The frontotemporal and vertex regions are joined together, and more significant is the extent of hair loss.
The most drastic hair loss stage, just a band of hair that goes around the head’s sides, persists. Usually, this hair is not thick and could be dainty.
Norwood Class A.
That is a somewhat different and less common hair loss classification. Norwood also defined a Type A variant, distinguished by two major features and two minor features, from its standard classification system.
Understanding the Female Pattern Hair Loss
Female pattern hair loss (FPHL) is a distinctive form of diffuse hair loss in females with androgenetic alopecia. FPHL affects lots of women. Approximately 40 percent of women age 50 show signs of hair loss, and less than 45 percent of women age 80 with full hair.
FPHL is quite different from the more easily recognizable baldness of the male pattern, which usually begins with a receding frontal hairline, which progresses up to a bald patch on top. It is very uncommon for women to bald after the male pattern unless the body’s excessive production by androgens is present.
What Causes Female Pattern Hair Loss?
FPHL’s genetic predisposition is strong. The inheritance model is polygenic, indicating that many genes contribute to FPHL. Neither parent nor both could inherit those genes. Genetic testing is not currently recommended for assessing the risk of balding, as it is unreliable.
Diagnosis of Female Pattern Baldness
In women, hair loss is not always as straightforward as in most men. In men, hereditary male pattern baldness causes about 90 percent of all cases. In women, however, a multitude of conditions and circumstances can trigger hair loss.
Tests for Hair Loss in Women
- Hormone levels
- Serum iron, serum ferritin, and total iron-binding capacity
- Thyroid levels
- VDRL (a screening test for syphilis)
- Complete blood count
- Scalp biopsy
- Hair pulling
Density Scales of Hair Loss in Women
Most hair loss specialists use two widely known female hair loss-density scales: the Ludwig Scale and the Savin Scale. They are similar except the Savin Scale also measures thinning entirely.
What is Savin Scale?
The Savin scale is a form of evaluative chart commonly used in female patterns for measuring the most common types of hair loss (FPH). It is often used to describe the different degrees of hair thinning and list typical patterns of FPH.
How Does the Savin Scale Measure Hair Loss?
The Savin scale provides alpha-numerically coded images that depict various types of FPH and at multiple stages. These images measure hair loss in 3 areas of the scalp. They are:
This scale measures hair loss around the hairline and temples, typically more prevalent with male hair loss patterns (MPH) than with FPH, but can still occur with FPH. If there is FPH frontal hair loss, the hairline corners begin to recede until only hair on the head, and mid-scalp sides eventually appear. The alpha-numeric code ranges from F1 (minimal hair recession) to F6 (massive mid-scalp-recession).
This scale measures hair loss occurring right in the middle of the scalp. Loss of hair in this region begins as a widening part, which eventually becomes a circular area of loss. The alpha-numeric code ranges from M1 (which looks like a normal part) to M5 (which in the middle of the scalp is a circular patch of hair loss).
Again, this is much more prevalent with MPH and tends to happen with FPH, though usually to a lesser degree. Loss of crown hair refers to thinning at the top of the head, backward. For this region, the alpha-numeric code ranges from V1 (little loss) to V7 (a large circular patch of hair loss to the top of the back scalp).