There are various types of hair loss, while each of them has numerous causes. We select a number of common causes, and we would like to give you a better understanding.
Genetics
Almost everyone will notice hair loss or hair thinning as they enter their middle age. However, up to 40% of us will experience a more obvious, or faster form of this condition, and this is known as Hereditary-Pattern Baldness. Recently we have begun to understand more about mechanism of this type of hair loss: Hair growth cycle was changed under the influence of testosterone, which results in shorter or thinner hair. Hair growth in certain areas of the scalp will stop eventually, and causes this typical pattern of hair loss. Contrary to the common beliefs, this baldness is actually contributed by genes of both parents, rather than inherited from one's mother's family.
Immune system imbalance
Our immune system usually attacks the cause of infections, and is the natural defense system of our bodies, protecting you from bacteria and viruses. However, when the system is imbalance, it would damage the hair follicles instead. This is known as Alopecia Areata and scientists are still unclear about the reasons behind. Although, in many cases the hair grows back in a few months and the hair follicles are not permanently damaged, this condition is rather common among people with other autoimmune conditions, including diabetes and thyroid disease. This is also very common among people with Down syndrome, which is a genetic condition that causes learning difficulties and affects physical development.
Permanent damage of hair follicles
This is known as Scarring Alopecia and in many cases, it is the result of another condition, such as Scleroderma, a condition that affects the body's connective tissues, and results in hard, puffy and itchy skin, and Lichen Planus , a non-infectious, itchy rash that can affect many areas of the body.
Temporary hair loss
Also known as Telogen Effluvium, and can be caused by hormonal changes such as pregnancy, intense emotional stress, long-term illnesses such as cancer or liver disease, crash dieting and medications.