Baldness refers to any form of hair loss, temporary or longer lasting. in which, because of the thinning of hair, the underlying scalp becomes more readily visible. The most common form of baldness is hereditary, sex-linked, and is found in men: this form is inherited through the mother and passed on to the son. (It does not occur in women even when they carry and transmit the characteristic.) Being a female (with the accompanying female hormones) protects against this form of baldness. while being a male with male hormones predisposes.
Thus a woman whose brothers are bald may pass the characteristic on to her own son even though her husband, the father of the boy, has a good head of hair. The extent of hair loss in sex-linked baldness is variable, as is also the age at which it becomes obvious. There is no treatment of significant value for this form of baldness in men, although many ingenious approaches (including the rubbing-in of female sex hormones) have been tried.
There are temporary states of hair loss in women which may unnecessarily trouble them because of the fear of significant baldness: such women may be reassured that this will not occur. Such hair loss may be seen following pregnancy, some women complaining that hair is “coming out by the handful.” This form of hair loss is completely compensated for in the ensuing months.
Similar states of temporary hair loss may be seen following feverish illnesses, of which typhoid fever was once a prime example. It may be seen after some of the more common infectious diseases. Some glandular disorders may lead to noticeable hair loss: these include certain disorders of the adrenal glands and. perhaps somewhat more commonly, over- and under-function of the thyroid gland. With proper diagnosis and treatment for these conditions, however, regrowth of hair can be anticipated. Cracking and splitting of the hairs and increased shedding may occur because of some procedures applied to the hair. “Ponytails” and other styling procedures which pull unnecessarily on the hair may do this and are best avoided.