Hair loss can occur from many causes, including illness, stress, medications, and hormone changes. Thyroid problems are a well known cause of hair loss. But that is unlikely since your mother's thyroid test was normal.

Not all hair loss is a result of abnormal conditions. Hair loss can result from normal shedding. At times, shedding may be greater than usual. This can occur during "telogen effluvium," a normal "resting" phase of hair growth. Hair loss can also result with normal aging. This type of hair loss, called "androgenic alopecia," often has an inherited component. If other members of your mom's family have thinning hair, your mom may be more susceptible to hair loss as she ages.

"Traction," or pulling hair by vigorous combing, wearing hair pulled back in a ponytail, or braiding hair can also lead to hair loss, especially around the front portion of the scalp. Scalp conditions, as well as an "autoimmune" condition called "alopecia areata" can lead to hair loss.

Treating hair loss depends upon the cause. This may involve a change in medication and treating any underlying disorders. If hair loss is just related to aging or to telogen effluvium, Minoxidil, applied to the scalp, may result in the growth of some thin hairs. However, the effect is lost when the person stops using the product. Research is in progress to develop better treatments for hair loss.

A scalp biopsy may be helpful in determining the cause of hair loss. Examining the hairs under a microscope can reveal whether growing hairs or resting hairs are falling out. This can be helpful in determining the type of hair loss. Blood tests for abnormal hormone levels can also be helpful. Because there are so many causes for hair loss, it is important for your mom to see her doctor for an examination and treatment of any underlying conditions.