There are three main factors of hair loss: Age, genetics and hormones.
The Anagen (growing) phase of a young person can last up until seven years, while an older person has an Anagen phase of only 2-3 years. Getting bald is often a slow process, even though those experiencing it might not agree. As a measure, 30% of all men will experience balding at 30 years of age, 40% at 40 years and so on.
As we get older the diameter of each hair decreases. This is among other things a result of poor blood circulation to the hair. Massaging the scalp, for example with the fingers, regularly, improves circulation often to a noticeable degree. This is precisely what many undocumented hair loss products rely on. The buyer is asked to massage the scalp with cream or herbal oil, based on maybe a special formula, 2-3 times a day. This will often, after 6-12 months, reduce their hair loss. What the buyer often is unaware of is that by massaging the scalp with the hair loss treatment product he/she stimulates blood circulation to the hair, thus increasing growth. Circulation is important for hair to get enough oxygen and nutrition to continue growing.
Genes and pattern baldness
There are men with increased levels of DHT in the body, and yet have normal hair growth on the head. Somehow their hair roots are immune to the increased levels of DHT. This immunity is believed to be inherited through their genes. There are different theories, regarding the connection between inherited genes, DHT and hair loss.
Androgenic alopecia: It is a common form of hair loss in both males and females. In males, this condition is also commonly known as male pattern baldness. Hair is lost in a well-defined pattern, beginning above both temples. Over time, the hairline recedes to form a characteristic „M” shape. Hair also thins at the crown of the head. Often a rim of hair around the sides and rear of the head is left, or the condition may progress to complete baldness. The pattern of hair loss in women differs from male pattern baldness. In women, the hair becomes thinner all over the head, and the hairline does not recede. Androgenetic alopecia in women rarely leads to total baldness. Cicatricial alopecia: It refers to a diverse group of rare disorders that destroy the hair follicle, replace it with scar tissue, and cause permanent hair loss. In some cases, hair loss is gradual, without symptoms, and is unnoticed for long periods.
Alopecia areata: It is a condition affecting humans, in which hair is lost from some or all areas of the body, usually from the scalp. Because it causes bald spots on the scalp, especially in the first stages, it is sometimes called spot baldness. In 1%–2% of cases, the condition can spread to the entire scalp (Alopecia totalis) or to the entire epidermis (Alopecia Universalis). Conditions resembling AA, and having a similar cause, occur also in other species. Telogen effluvium: It is a form of non-scarring alopecia characterized by diffuse hair shedding, often with an acute onset. A chronic form with a more insidious onset and a longer duration also exists. Telogen effluvium is a reactive process caused by metabolic or hormonal stress or medications. Generally, recovery is spontaneous and occurs within 6 months.
Traction alopecia: It is a form of alopecia, or gradual hair loss, caused primarily by pulling force being applied to the hair. This commonly results from the sufferer frequently wearing his/her hair in a particularly tight ponytail, pigtails, or braids. It is also seen occasionally in long-haired toy dogs whose owners use barrettes to keep hair out of the dogs’ faces.
Hair loss and hormones
Hair loss is definitely connected to male hormones. One of which is the well-known testosterone. Much more important is the hormone Dihydrotestosterone (DHT)–which exists in large amounts, in dying hair roots, in balding men. DHT is formed in the oil glands and forces individual hair to become finer and shorter, becoming Vellus hair that remains. As mentioned earlier this is very fine and practically invisible hair. This Vellus hair, even in large amounts, is a poor substitute to real hair, as we know it. Ironically, DHT is responsible for the hair growth on other parts of our body, such as ears, nose and chest. Many bald men do have a lot of hair on their chest. This is the direct effect of the increased level of DHT. It causes hair on the head to stop growing while helping it to grow elsewhere.
Women can also experience hair loss, during the period after childbirth. During pregnancy, there is an immense increase in female hormones in the body. After birth, these hormone levels are reduced to normal again. It is believed that this sudden change in hormone levels can cause temporary hair loss.