Sleeping Position Affects the Hairline Recession in Male Patients with Androgenetic Alopecia

This study involving 161 male patients with androgenic alopecia found that sleeping position significantly affects hairline recession patterns, particularly in those with "M"-shaped hairlines. Patients who slept on their left side had more hairline recession on the left, while those who slept on their right side had more recession on the right. No significant difference was observed in hairline recession for those who slept in a supine position or had no fixed sleeping position. Combing direction did not impact hairline recession. The study suggests that prolonged scalp compression during sleep may restrict blood circulation, affecting hair growth, and highlights the importance of sleeping position in managing hairline recession. Further research is needed to understand the underlying mechanisms.