Are you sometimes worried about the amount of hair that you find in the shower drain? Of course excessive hair loss can be a result of a number of conditions including autoimmune disorders, hypothyroid, low iron, etc. We can be diagnose these with the right tests, but bear in mind that there are two seasonal spikes of hair loss that are normal. This recent paper in the journal Dermatology reports a study of 823 women in which “Analysis of trichograms demonstrated annual periodicity in the growth and shedding of hair, manifested by a maximal proportion of telogen hairs in summer. A second peak seems to exist, though it is less pronounced, in spring. The telogen rates were lowest in late winter.” [Trichograms are examinations of plucked hairs under the microscope. The telogen phase is the resting phase of the hair follicle during which hair is shed.] The authors conclude: “These results confirm the findings of former authors who have indicated seasonal changes in human hair growth, though this is the first study performed systematically in a representative number of women.”