Objective: To examine trends in diagnosis of gender dysphoria and related conditions in children and young people attending primary care practices in England., Design: Longitudinal analysis of electronic primary care records from the Clinical Practice Research Datalink (CPRD) Aurum database linked to hospital and Index of Multiple Deprivation data., Setting: Primary care practices in England between 2011 and 2021., Participants: 3782 patients aged 0-18 years with a recorded history of gender dysphoria/incongruence and matched comparators with autism spectrum conditions or eating disorder., Main Outcome Measures: Incidence rates and prevalence of gender dysphoria/incongruence; prescribing rates for medical treatments; co-occurrence of anxiety, depression and self-harm., Results: Between 2011 and 2021, incidence rates of recorded gender dysphoria/incongruence increased from 0.14 (95% CI 0.08 to 0.20) to 4.4 (95% CI 4.1 to 4.7) per 10 000 person years, and from 2014 the rate increased more rapidly in recorded females than males. There was no significant association between gender dysphoria/incongruence and area level deprivation. Of the 3782 children and young people with a record of gender dysphoria/incongruence, 176 (4.7%) were prescribed puberty suppressing hormones; 302 (8.0%) were prescribed masculinising/feminising hormones; and 1994 (52.7%) had a record of anxiety, depression or self-harm. Compared with matched comparators, those experiencing gender dysphoria/incongruence had similar recorded rates of anxiety and higher rates of depression and self-harm., Conclusions: Recorded prevalence of gender dysphoria/incongruence increased substantially in children and young people between 2011 and 2021, particularly in recorded females. Levels of anxiety, depression and self-harm were high, indicating an urgent need for better prevention and treatment of mental health difficulties in these patients., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2025. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.)