Hair Loss Problems...

Hair loss is not a trivial condition, the process leading to alopecia may take years to complete or it may occur in a relatively short time as with chemotherapy induced hair loss.

For hair loss to become visible, the balance between the loss of hair and the production of new hair by the hair follicles has to be disturbed.

Normally between 50-100 hairs are lost each day. Hairs are produced by the rapidly dividing matrix cells in the bulb of the hair follicle, this can be affected by various different factors and processes.

Throughout our lives hair is produced, it grows and it is shed from the body. If all hairs were to be shed at the same time we would all experience alopecia. So soon after birth the synchronicity of hair growth is broken and all of the hair follicles in the scalp develop their own cycle. So at any one time hairs are in different stages of development and when they are lost and replaced by new ones the individual is unaware of the changes.

Hair is produced from keratin, it does not have any blood supply. The hair on our scalp is produced from the 100,000 to 150,000 hair follicles found on all of our scalps and at any one time approximately 95% of all hair follicles will be in the active growth phase.

The hair growth cycle consists of three distinct phases.

•  Anagen Phase – this is the growing phase in which the hair shaft is produced and it will continue to lengthen for between 2-5 years in most people although it can grow for longer on some individuals. This period of growth shortens as age advances.  In a normal healthy individual scalp hair will grow between 1.5-2.0 centimetres per month. 
                                        
• Catagen Phase – this phase follows the growing phase and it marks a period of time when the hair follicle is resting in a mode of suspended animation. No growth will occur in this period usually lasting for 2-4 weeks 
                                                                            
• Telogen Phase – This is the last part of the growing cycle where the hair rests for 5-6 weeks and then falls out naturally; this process is called shedding of the hair. In a normal person a total of 50-100 hairs are lost each day although it can appear to be more if the hair is washed infrequently.

In the process of hair loss, firstly the hair follicles undergo a shortening of the duration of the anagen phase. The hair follicles then undergo a miniaturisation of the hair follicles as the process continues the hair follicles become smaller and the hairs become shorter. This process of attack by androgens primarily affects the front of the scalp, the temporal, frontal and vertex areas (crown of the head).

The reduction in duration of the anagen phase means that more hairs will be in the telogen phase and they will be in this phase of the growth cycle for longer periods of time. As this phase does not permit growth of the hair shaft, it will result in increased hair loss and the effects will accumulate to cause baldness.

In this process, not only the size and the number of hairs decrease but hairs in the telogen phase are more likely to suffer damage and this explains why there is increased hair loss when the hair is washed. The process of androgenetic hair loss can result in a fine covering of hair that can be difficult to see as they contain little or no pigment.

Male Pattern Baldness can occur at any age after puberty when blood androgen levels rise. The first change seen is a reduction of hair in the region of the temples. This is a very common finding and is present in approximately 96% of sexually mature Caucasian men, but not all of these individuals will go on to develop alopecia.

Alopecia areata 
May occur with types of thyroid disease, pernicious anaemia, rheumatoid arthritis vitiligo and diabetes mellitus. There is a family history of the condition in more than 10% of cases. In this process damage to the hair follicles occurs which then causes a progressive weakening of the hair shaft resulting in this breaking and therefore shortening, hair often regrows but may take more than a year and it may lack pigment causing a white hair appearance. It can be severe and involve the whole body, this is referred to as universalis or totalis.
Diffuse alopecia usually occurs in females and frequently there is a triggering factor, a fungal infection of the scalp may be present, this requires appropriate treatment that is available through a pharmacy or by prescription from your General practitioner.

Diffuse alopecia
Can occur following the birth of a child, during pregnancy, the high levels of oestrogen can result in less than normal hairs being shed, once the baby is born and the oestrogen levels are reduced this may lead to a large quantity of hairs follicles progressing into the telogen phase, this is where the hair follicle moves into the shedding phase of its growth cycle, and a significant number of hairs are shed at the same time.
Other factors may include stress, drugs such as those used to thin the blood (anticoagulants), antidepressants, and some drugs that are used to lower the blood pressure. It is advised that should this occur then help should be sought from your general practitioner in order to clarify the risk.
Excessive use of bleaches and cosmetic agents may cause the hair to become more fragile causing the shaft to break off.

Androgenetic alopecia
 is the commonest cause of thinning hair, it is genetically determined and occurs in both males and females, this is more commonly known as male or female pattern baldness.

Male hair loss, under the action of male sex hormones which are called androgens the hair follicles undergo several changes which lead to alopecia.

Female hair loss
Hair Loss due to androgenetic alopecia is also found in women, although many women today are not aware of this fact. It is noticed later in life in females compared to males: in females androgenetic hair loss first becomes apparent in the 3^rd-5^th decade of life, whilst in men it appears in the 2^nd or 3^rd decade.
In women it is particularly likely to develop at times of hormonal change including those dictated by life-style choices. These will include initiation or stopping of the contraceptive pill, the period immediately after the birth of a baby (post-partum) or in the periods of time before and soon after the menopause. In most women with androgenetic hair loss there is no abnormal androgen production.
Many women who present with androgenetic hair loss in middle age can have experienced an exacerbation of their condition due to medical factors such as iron deficiency anaemia or a low activity of the thyroid gland (hypothyroidism)
One major difference between the sexes is that females rarely suffer from total baldness and the end result is usually decreased hair density in the affected areas.