Androgenetic Alopecia (AGA): This is the most common form of hair loss in both men and women. In men, this is known as male pattern baldness. In women, this is referred to as female pattern baldness. Three factors interact to produce hair loss: aging, hormones and genetics. Hair loss progression tends to follow a distinctive pattern, and does not get better on its own.

Hormone disorders: Hormone imbalances such as hypothyroidism or hyperthyroidism may cause hair loss in both men and women. In women, excess androgen production due to polycystic ovary syndrome (PCOS) may increase hair loss. Hair loss may be reversed if the underlying hormone disorder is corrected.

Alopecia Arreata: In alopecia areata, the immune system mistakenly attacks hair follicles. Unpredictable, patchy hair loss is a common sign of this condition. Hair may grow back on its own or with treatment.

Medications: Some medications may cause hair loss as a side effect. These include certain cancer treatments, blood thinners, cholesterol-lowering drugs and Vitamin A-based medications. Medication-induced hair loss is often reversible.

Nutritional deficiencies: Nutritional deficiencies such as iron deficiency may cause hair loss. Iron promotes the formation of healthy red blood cells, which oxygenate the cells that support hair growth. Hair loss is a common symptom of iron deficiency anemia. Hair loss can be reversed if the underlying deficiency is corrected.

Stress: Hair loss may occur after a person experiences severe stress. Treatment options are available that may help with this form of hair loss, although hair will often grown back on its own.

Hair treatments and hair styles: Certain hair treatments such as hot oil may damage hair and increase the fragility of hair strands. Frequent use of curling irons and high-heat settings of the blow dryer can also weaken hair. High tension hair styles such as tightly pulled-back pigtails, cornrows and braids can put stress on the hair and cause hair loss over time.

A hair follicle is a tube-like structure that surrounds the root and strand of a hair, and occupies the top two layers of skin - the dermis and epidermis. The function of the hair follicle is to grow your hair, and it does so in cycles of activity and rest:

Anagen: Active growth phase. The hair strand starts growing from the root (dermal papilla) of the hair follicle. The strand is nourished with the blood supply and nutrients it needs to grow. Hair growth is roughly 1cm per month, and the anagen phase can last for several years.

Catagen: Transition phase. During this phase, transition occurs from a growing to a resting phase. The hair strand detaches from the blood supply, while the hair follicle shrinks as it prepares to enter the resting phase. This transition takes a few weeks.

Telogen: Resting phase. Hair growth is in the inactive or resting phase, and hair strands will shed or fall out of the hair follicle. This phase often lasts 3 to 4 months.

Each hair follicle is independent of one another, and goes through the growth cycle at different times - otherwise all of your hair would fall out at once! Instead, you only shed 50 to 100 hairs per day on a healthy head of hair.

Male pattern baldness, also known as male androgenetic alopecia (AGA), is the most common cause of hair loss in men. Three factors interact to produce this: aging, hormones and genetics. Hair loss tends to follow a distinct pattern over time.

Hair loss can begin as early as the late teens or early 20s. By the age of 50, up to 50% of men will experience male pattern baldness to some degree.

Androgens are hormones that support male sexual development, and play a significant role in other functions, including sex drive and regulating hair growth. Testosterone is an important androgen, and is converted into dihydrotestosterone (DHT) through the enzyme 5-alpha reductase. The action of DHT is associated with hair loss.

When circulating DHT binds to androgen receptors in the hair follicle, it can shorten the anagen or hair growth phase more and more with each cycle. The telogen resting phase on the other hand can remain the same or become longer. This causes a process known as follicular miniaturization, which leads to thinner and shallower hair follicles over time, and thinner and shorter hair strands as a result.

Those experiencing male pattern baldness will notice a decline in hair volume, density and quality as the condition progresses. This is because hair will not grow as much before it is shed, and it will take longer for hair to start growing back after it is shed. Eventually, the hair growth phase becomes so short that the hair strand doesn’t even reach the surface of the skin before it stops growing, leading to a lack of visible hair.

In male pattern baldness, there may be an increased production of dihydrotestosterone, higher levels of 5-alpha reductase (which converts testosterone to DHT) and more androgen receptors in the balding scalp. Genetics play a role in that there is a strong correlation with family history of male pattern baldness.

The Hamilton–Norwood scale is commonly used to visualize the stages of male pattern baldness.

In men, hair loss usually begins around the temples, and the receding hairline eventually forms a characteristic "M" or “U” shape. Hair at the top of the head also thins, often progressing to baldness without treatment.

Stage 1: Little or no hairline recession.

Stage 2: Slight recession of the hairline around the temples.

Stage 3: Deep hairline recession around the temples which resembles an “M” or “U” shape.

Stage 3 (Vertex): Hairline recession around the temples, plus loss of hair at the top of the scalp, also known as the vertex.

Stage 4: Deep hairline recession and significant hair loss on the vertex. The two areas of hair loss are separated by a band of hair, which will gradually shrink as hair loss progresses.

Stage 5: The two areas of hair loss are larger than in stage 4. They are still separated, but the band of hair between them is narrower.

Stage 6: The balding areas at the temples join with the balding area at the vertex. The band of hair across the top of the head is gone or sparse.

Stage 7: No hair remains at the top of the head, and only a thin band of hair remains around the side of the head.

Note: the Hamilton-Norwood scale is not a definitive means for evaluating male pattern baldness; your medical professional will also use other diagnostic methods for a complete evaluation.

Why is male pattern baldness important to treat?

Male pattern baldness is progressive, and will not get better on its own. Treatment is required to prevent further hair loss. Although seeking treatment is a personal choice, hair loss may have a significant impact on one's sense of well-being.

Many men consider their hair to be an essential part of their identity and appearance. If you feel that loss of hair will affect you negatively, it is important to take action and seek treatment.

Female pattern baldness, also known as female androgenetic alopecia (AGA), is the most common cause of hair loss in women. Three factors interact to produce this: aging, hormones and genetics. Hair loss tends to follow a distinct pattern over time.

Hair loss can begin as early as the late teens or early 20s, though the frequency increases with age and is often first noticed during post-menopause. More than 50% of post-menopausal women may experience some element of female pattern baldness, such as hair thinning or bald spots.

Androgens are hormones that support sexual development in males, and also play an important role in other functions for both men and women, including sex drive and the regulation of hair growth. Women produce androgens in much smaller quantities than in men. Testosterone is an important androgen that is converted by the body into dihydrotestosterone (DHT) through the enzyme 5-alpha reductase. The action of DHT is associated with hair loss.

When circulating DHT binds to androgen receptors in the hair follicle, it can shorten the anagen or hair growth phase more and more with each cycle. The telogen resting phase on the other hand can remain the same or become longer. This causes a process known as follicular miniaturization, which leads to thinner and shallower hair follicles over time, and thinner and shorter hair strands as a result.

Those experiencing female pattern baldness will notice a decline in hair volume, density and quality as the condition progresses. This is because hair will not grow as much before it is shed, and it will take longer for hair to start growing back after it is shed. Since women usually produce much smaller amounts of androgens than men, the precise role of androgens in female pattern baldness is less clear, although excess androgen production such as in PCOS are clearly linked with hair loss.

Genetics play a role in that there is a strong correlation with family history of female pattern baldness.

The Ludwig scale is commonly used to visualize the stages of female pattern baldness:

In women, hair loss begins with gradual thinning at the part line, followed by increasing hair loss radiating from the top of the head. A woman's hairline rarely recedes, and women rarely become bald.

Stage 1: Mild hair loss at the parting line. It may not be noticeable at first since the rest of the hair remains thick, but becomes increasingly noticeable over time as hair loss increases. The scalp is more visible when hair is parted down the center.

Stage 2: Visibly more thinning and scalp visibility than in stage 1. The volume of hair has decreased significantly.

Stage 3: The final and most severe type of female pattern baldness. Thinning has progressed noticeably and it is difficult to conceal the bald area.

Note: the Ludwig scale is not a complete tool for evaluating female pattern baldness; your medical professional will also use other diagnostic tools for a complete evaluation.

Why is female pattern baldness important to treat?

Female pattern baldness is progressive, and will not get better on its own. Treatment is required to prevent further hair loss. Although seeking treatment is a personal choice, hair loss may have a significant impact on one's sense of well-being.

Many women consider their hair an essential part of their identity and appearance. If you feel loss of hair will affect you negatively, it is important to take action and seek treatment.

Hair Self-Care

Hair self-care routines can help preserve and strengthen existing hair, no matter what stage of hair loss you are experiencing:

Gentle cleansing and moisturizing: It is best to use a gentle cleansing shampoo that does not remove moisture from hair. Afterwards, apply a moisturizing conditioner to help maintain moisture in the hair and to reduce the chances of hair breakage and split ends. Avoid products that contain parabens and silicone, which can undermine hair health.

Nourishing the hair: Applying hair products containing vitamins and supplements can fortify hair and reduce damage. Some examples include biotin, vitamin E and amino acids.

Reducing heat and tension in hair routines: Heat can damage hair and make hair strands more fragile. Limiting curling irons to special occasions rather than daily use, and lowering the heat setting on your blow dryer can reduce heat-related hair stress. Avoiding hairstyles which place strain on hair, such as tightly pulled back buns, ponytails, cornrows, or braids will reduce tension-related hair stress.

Non-Prescription Products

Minoxidil (in topical forms up to 5%): Minoxidil can help increase the blood flow to hair follicles, and stimulate the hair follicle to transition from the resting phase (telogen) to the active growth phase (anagen).

Saw palmetto: This botanical extract is an active ingredient found in natural hair loss prevention products. It is a natural 5-alpha reductase inhibitor that reduces the conversion of testosterone to DHT, combating this leading cause of hair loss.

Prescription Medications

Finasteride: This pharmacological 5-alpha reductase inhibitor prevents the conversion of testosterone to DHT, a major cause of hair loss. It is available in oral and topical forms. It is not suitable for women of child-bearing age. A thorough consultation with your doctor is required to determine if this is right for you.

Spironolactone: This medication may be prescribed for women that are experiencing androgen over-production, such as in polycystic ovary syndrome (PCOS). Excess androgens are linked with excessive hair shedding.

Medical Procedures

These procedures may be suitable for more advanced stages of hair loss not responding to the options mentioned above.

Hair transplant surgery: This involves removing a strip of scalp from the back of the head and using it to fill in a bald patch. A narrow strip of scalp is removed and divided into hundreds of tiny grafts, each containing a few hair follicles. Slits in the bald scalp are then created using a blade or needle, and a graft is planted in each slit, from which hair will grow.

Platelet Rich Plasma: Platelet rich plasma (PRP) therapy involves drawing some of your own blood, then spinning it in a centrifuge to obtain an extract that has a high concentration of platelets. This extract is injected into areas of hair loss across the scalp. It is thought that platelets may stimulate dermal papilla cells at the follicle root which play an important role in hair growth.