Hair is a tissue which has a rapid turnover rate compared to most tissues in the body. It is therefore quite susceptible to fluctuations in the body’s normal state of balance. Hair is also very hormone sensitive and is therefore susceptible to changes in certain hormonal systems which operate in the body.
One of these hormonal systems is that of the thyroid gland.
Thyroid and hair loss
Both an under-active thyroid gland (hypothyroidism) and an overactive thyroid gland (hyperthyroidism) can lead to hair loss. Checking the thyroid hormone levels is one of the first things that most doctors would do when a patient has a sudden onset of abnormal hair loss. Thyroid-related hair loss problems are usually not difficult to diagnose as the clinical symptoms and signs of both hyperthyroidism and hypothyroidism are most often quite obvious.
In hypothyroidism, patients lose hair all over the head and the remaining hair takes on a coarse texture. In hyperthyroidism, the hair loss is again diffuse, but the hair texture remains unchanged.
Fortunately, thyroid-related hair loss is temporary. Once the thyroxine (thyroid hormone) level has been corrected, the hair loss will cease and the hair texture will return to its previous state.
Other causes of temporary hair loss
Factors such as illnesses, anaesthetics, certain drugs, emotional traumas and fevers create hormonal fluxes in the body which accelerate hair turnover. If there is no underlying genetic or pathological condition present, this is usually a temporary state of affairs and the increased turnover of hair returns to a normal state once the trigger factor is no longer present. The medical name for this state of temporary increased hair turnover is Telogen Defluvium.
Telogen Defluvium is commonly seen in women about four to six months after giving birth, as the very high oestrogen levels achieved in pregnancy hit rock bottom, creating a massive hormonal flux.
This hair loss is usually temporary, lasting only a few months. If it continues beyond this point and leads to permanent thinning of hair, this usually implies that there is another inherited or pathological problem present.
Certain drugs, especially chemotherapy drugs, are known to make one’s hair fall out. In almost all cases this is a temporary situation which corrects itself once the drug is removed. Hair will normally start growing again about three months after
chemotherapy has ceased.
Iron and Vitamin A
Iron deficiency and vitamin A toxicity are two nutritional causes of hair loss. Iron deficiency-related hair loss occurs when one’s iron is very low. It is an uncommon form of hair loss as the low iron level is normally picked up and treated early on, due to symptoms of fatigue and pale complexion.Vitamin A toxicity is more common as people do not realise that vitamin A is a fat soluble vitamin and cannot easily be released from the body. One gets vitamin A from one’s diet especially in the form of yellow and orange vegetables such as gem squashes, butternuts and carrots. If one is also supplementing by taking vitamin A in tablet form, one is likely to overdose. Your recommended daily allowance for vitamin A is five thousand international units per day. Any supplement containing more than two thousand five hundred international units of vitamin A would put you at risk of overdosing on a daily basis. The vitamin A would accumulate in your system and be a minor cause of hair loss.
Both iron deficiency and vitamin A toxicity result in a diffuse thinning of hair all over the head. They are both avoidable causes of hair loss.
Menopause is another condition in which the body’s state of hormonal balance is upset, leading to hair loss. Prior to menopause, a women’s natural oestrogen keeps the hormonal balance by countering the effects of the male hormone dihydrotestosterone (DHT).
DHT is the hormone responsible for shrinking one’s hair follicles leading to baldness and permanent thinning of hair.
Post-menopause, this balancing effect is lost, and even if a woman is taking hormone replacement therapy, this is usually not adequate to stem the effect of the DHT.
DHT works its shrinking effect on the hair follicle cells by binding to genetically-inherited receptors in the base of the hair follicle. The more receptors that one has, or the more sensitive these receptors are to the DHT, the faster and more severe the shrinking of the follicles will be. This is why women who have a family history of baldness on either side of the family are more likely to thin their hair pre- and post menopause than those with no family history of hair thinning. The condition which results from the shrinking of the hair follicles is called alopecia androgenetica or male/female pattern baldness.
Alopecia androgenetica or male/female pattern baldness is by far the most common hair loss condition which leads to permanent thinning of hair in both men and women. It affects about 80% of men and about 40% of women, and is far and away the most common condition which I treat at my hair loss clinic in Bedfordview.
This condition is inherited from both sides of the family, and can go back six generations, sometimes skipping a generation or two. It is a complex form of inheritance, as the genes for baldness are located in multiple locations on many different chromosomes. It is therefore not easy to predict whether a child will suffer from this condition until their hair starts to thin sometime after puberty.
The hair will thin in specific patterns dependent on the distribution of the genetic receptors on the scalp. In women, this tends to be focused on the crown and sides of the head, with the back of the head being less severely affected.
In men the receptors are located only on the top of the head, hence the reason why men tend to only go bald on the top of the head. Males also have four hundred times the amount of DHT circulating in their bloodstreams compared to women, causing balding to occur more rapidly and more severely than it does in females.
Everyone has a certain amount of DHT-sensitive receptors in the base of their hair follicles. This is the very reason why almost everyone will thin their hair to a certain extent as they age.
People who suffer younger in life with thinning hair have inherited a greater amount of hormone receptors in their hair follicles, or a greater sensitivity of their receptors to DHT.
Thinning of hair has long been believed to be a natural part of the aging process, and most people believe that there is nothing that can be done about it. This is no longer the case.
There has been a revolution in recent years with respect to medical treatments, i.e. tablets and topical prescription medicines which have been developed to not only stop the thinning of hair that occurs with ageing or alopecia androgenetica, but to actually reverse it.
The general public has very little knowledge of the fact that the latest prescription medical treatments for hair thinning will deliver excellent regrowth results in a high percentage of both men and women.
These latest drugs work their effect by re-creating the environment around a person’s hair follicle that existed when that person was about ten years of age, i.e. before that person went through puberty and before the genetic and hormonal factors came into play.
Factors such as age, degree of thinning and the amount of time that one has thinned one’s hair, do make a difference in terms of response to medical treatment, but they are not the most important factors that determine the outcome of treatment.
By far the most important factor determining the outcome of medical treatment for hair thinning is the sensitivity of an individual’s genetic receptors to medical treatment. This is an unknown factor before one commences with treatment, but it does not take too long to find out what type of responder one is going to be.
The earliest that one can see photographic evidence of regrowth of thicker, stronger hair is usually at three months from start of treatment. The longest that it could take is about six months. Some patients respond extremely quickly, showing evidence of regrowth after only one month. This however is the exception to the rule.
The reason that one can see results so quickly with medical treatment is because the treatment doesn’t just work on bringing new hairs out thicker and stronger. New hairs only comprise about one percent of all the hairs on one’s head, and it would take months to see photographic changes if the treatment worked only on new hairs.
Medical treatment however works on all of one’s existing hair follicles, growing all the hairs back thicker and stronger. It also increases the rate at which the hair grows. Normally hair grows at a rate of five to seven millimetres per month. On medical treatment, the hair can grow at speeds of eight to ten millimetres per month.
The best regrowth normally occurs between three months and nine months, and then it tends to plateau towards one year. At one year, the patient would go on to maintenance treatment to ensure that the regrowth is maintained.
Remember that alopecia androgenetica is a genetically-inherited condition and can therefore be effectively controlled but not cured. You would need to use one or other form of maintenance hair loss drug for life to maintain the effect.
This is much the same for all other genetically inherited conditions such as hypertension (high blood pressure) or hypercholesterolaemia. In the case of hair loss treatment, the drug is forming a barrier between your genetically inherited receptors and the hormone DHT which is trying to access it. Provided that the DHT cannot access the receptor, the follicle cannot shrink. If you decide to stop using the drug, the barrier comes down and the DHT will interact with the follicle once more, causing the follicle to begin shrinking once again.
For most male and female patients, using the medicine daily on an ongoing basis is not a major problem, since the hair regrowth result is worth it. Maintenance for a female patient usually involves applying one topical lotion to the scalp twice daily and washing the hair on a regular basis.
Maintenance for men usually involves swallowing a tablet daily, and maybe applying a topical lotion.
In conclusion, hair loss is a complex condition affecting a large proportion of both males and females. The causes of hair loss are varied, as are the means of treating the problem. Huge advances in terms of medical treatment in recent years for the most common hair loss conditions has brought about an end to the suffering of thousands of men and women, who in the past would have had to bear the psychological and social trauma associated with an embarrassing hair loss problem.