Mary Ann: Hair loss can occur in response to stressors like
a high temp or serious illness, and it is not at all an uncommon response
postpartum due to withdrawal of pregnancy hormones. It has nothing to do
with breastfeeding. What happens is that there is a cycle of growth and
shedding in hair follicles which is altered by the high  levels of
estrogen in pregnancy so that hair stays in a growth cycle longer than it
ordinarily would. This can make hair seem thicker during pregnancy.
With the hormonal adjustments after birth, more hair follicles go into a
shedding cycle so it does seem like the woman is losing hair by the
handful.  This a normal phenomenon and will rectify itself in a few
months. In the meantime, it may be a good time to get hair trimmed since
having split ends can make hair look even thinner, to experiment with a
different hair style, and to just be patient.

Ione Sims, GNM, IBCLC