DHT stands for dihydrotestosterone and is derived from testosterone, the male sex hormone. An enzyme known as 5a-reductase, synthesizes testosterone and converts it into DHT. Changes in the body’s metabolism of DHT can play a significant part in hair loss, as it is this substance that effectively strangles hair follicles and renders them permanently inactive.
DHT-related hair loss is often known as male pattern baldness to the layman, the medical term is known as androgenic alopecia or androgenetic alopecia. It is hereditary and those with fathers who had hair loss, often from an early age, are more likely to incur the same hair loss. Although not common in women, it does happen.
There are different forms of DHT which are dictated by the different types of 5-alpha reductase. Type 1 if found mainly in the skin’s sebocytes and in epidermal and follicular keratinocytes, sweat glands and dermal papilla cells. Type 2 is found in the seminal vesicles, prostate and the inner root sheath of the hair follicle. It is the type 2 that is the most closely linked to male pattern hair loss.
The hair follicles become sensitive to DHT and this causes the follicles to shrink and unable to hold hair roots. Dermal papilla or papilla of the hair is an essential part of the hair follicle as it is the part which is responsible for the growth of the hair. The necessary nutrients for good hair follicle growth come from the blood capillaries of the skin which in turn are in contact with the papilla. For good healthy hair growth the papilla must receive the nutrients and blood flow without loss.
DHT has a detrimental effect on the working of the dermal papilla. It prevents the hair follicles from receiving the essential nutrients that they require to produce healthy strong hair. If the hair follicles do not get the nutrition they require then the ‘rest periods’ become longer and the growth period shorter. Just as with the body, without a good healthy diet it can affect how we perform. For instance, during illness we will sleep longer and have a shorter time awake until our bodies are able to absorb the correct nutrients again.
The shrinking of the hair follicle is commonly known as miniaturization. As the hair follicle shrinks it can no longer hold a strong hair root and so the hair becomes thinner and finer until it no longer produces any hair at all. This fine type of hair is known as vellus hair and can be seen on all parts of the body except the soles of the feet, palms of hand and lips.
The production of DHT in a person is greatly dependent on genetics. It is passed down through generations and for some this can be a cause of concern. Over recent years many men have not wanted to accept they are going bald and want to be able to have a head of hair. Whilst DHT cannot be stopped there are medications available that can help to slow down the process. The earlier it is treated the better the success.
Dutasteride, finasteride and minoxidil are medications that are used for male pattern baldness. These have to be used under medical supervision as there are often side effects which could cause more problems. Finasteride is thought to cause sexual dysfunction which could be permanent so it is vital that any medication is strictly monitored.
With the advancements in technology and medications some of the hair loss can be reversed depending on the strength of DHT. Slowing down loss of hair has become possible but damaged hair follicles cannot be reversed. Hair transplants are available where hair from the back of the head is transplanted to the damaged follicles. This can leave scarring and can be a painful procedure that takes time before results are seen. More recently, alternative solutions such as scalp micropigmentation are rapidly gaining in popularity due to the permanency and non-invasive nature of such treatments.
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