Headache and Hormone Use Among Transgender Population in Thailand: A Cross-Sectional Online Study

The goal of this observational study is to learn how common headache and migraine are and to describe headache patterns among transgender adults in Thailand. The main questions it aims to answer are: * How common are headache and migraine among transgender adults in Thailand? * What headache patterns and levels of headache-related disability do participants report? * Are gender-affirming hormone therapy, gender-affirming surgery, or HIV pre-exposure prophylaxis (PrEP) use related to headache or migraine? About 500 transgender adults aged 18 years or older who currently attend or previously attended the Tangerine Clinic in Bangkok, Thailand, will take part. Participants will: * Provide consent online * Complete an online questionnaire about their general health and headache symptoms * Answer questions about gender-affirming hormone therapy, gender-affirming surgery, and PrEP use * Complete questionnaires that screen for migraine and measure how headaches affect daily activities This study will not assign any treatment or change the participants' usual medical care.