A recent study has found that summer and fall were associated with greater hair loss.
The new study explores the relationship between seasonality and hair loss at a population level using Google Trends data.
Across all eight countries, researchers analysed in the study that summer and fall were associated with greater hair loss.
The findings support previous studies that were constrained by small sample sizes or homogeneous populations in limited geographic locations.
The physiology of hair loss as related to seasonal variation is, however, unknown.
Senior author Dr. Shawn Kwatra from the Johns Hopkins University School of Medicine said that the study synthesised digital epidemiological data from both hemispheres to confirm the clinical suspicion that the summer and fall seasons are associated with greater hair loss.
"This finding is clinically relevant for patients presenting in the summer and fall months with worsened hair loss and has implications for assessing the effectiveness of therapies," Kwatra added.
Future research will further clarify this association and examine the physiology of the hair cycle, the researchers noted.
The research appeared in the British Journal of Dermatology.