Hair loss, baldness, and alopecia are all interchangeable terms meaning the same thing: there is hair missing, either complete or partial. However, the societal stigma associated with hair loss is the same with either partial or complete hair loss, as it serves to make a person less “aesthetically pleasing” according to societal standards.
So the question becomes, what exactly causes hair loss? Actually, there are many causes for hair loss and unfortunately, genetics is one of the most common causes in both men and women.
Hair Loss: The Causes
There are many causes for hair loss in women. Typically, baldness is not caused by a disease (though it is possible), but is based on heredity, levels of testosterone, and aging. However, there are additional causes for hair loss in addition to your genetics. These causes include:
- Age
- Autoimmune disorders or conditions
- Burns
- Certain medications
- Certain hair care products
- Excessive blow drying or shampooing
- Fever
- Habitual hair pulling
- Hormonal changes
- Infectious diseases
- Poor nutrition
- Radiation therapy
- Scalp ringworm (tinea capitis)
- Stress, emotional or physical
The Genetics of Hair Loss
It is common for excessive hair loss (more than 100 strands of hair lost per day) to be caused by your genetics, the factors inherited from both your mother and father. It was originally thought that the genes for hair growth and loss were located on the X chromosome. However, research has proven that there are many genes responsible for hair growth and hair loss, making hair maintenance and development a polygenic trait.
However, the presence of female and male pattern baldness is commonly noted to be an X linked trait. Women have two X chromosomes, while men have one. This is why male pattern baldness is markedly more common. The second X chromosome in women is often times enough to mask the presence of the first X chromosome when it has the gene encoding for female pattern baldness. However, men have only one X chromosome, so there is no masking possible.
Hair Loss: It is Commonly Inherited
The most common cause of hair loss in both women and men is actually due to genetics, as genes affect the overall process of how your hair grows and is maintained. They also encode for the sensitivity of your hair to certain products (most commonly noted of which is DHT, dihydroxytestosterone). Inherited hair loss is typically present by 50 years of age and tends to follow specific patterns, known as female pattern baldness and male pattern baldness.
Genetics and Your Hair
Genetics also determine many other features of hair, including the maximum length of hair growth, hair shaft diameter, hair color, the tendency for hair to curl or stay straight, the tendency for the development of gray hairs, and the rate at which your hair grows.
While genetics may be the main cause for both male and female hair loss, it is important to remember that there are other factors that affect your hair and hair loss.
Sources:
http://www.nlm.nih.gov/medlineplus/ency/article/003246.htm
http://www.webmd.com/skin-problems-and-treatments/hair-loss/tc/hair-loss-cause
