1. Aims: Disease susceptibility and the contributions of daytime napping to these diseases change along with aging. We aims to capture the trend in which daytime napping affects human health conditions in different age groups. 2. Scientific rationale: The role of daytime napping in maintaining body health was said to be different in children and adults. At the same time, academic investigators did not get a putative perspective whether daytime napping is good or bad for people. To solve the puzzle, we designed a study using UK Biobank genotype and phenotype data stratified by age groups. In this way, we are able to infer the casual relationship between daytime napping and many other human traits, hence, bring up a more comprehensive perspective of the consequences of daytime napping. 3. Project duration: Two years will be needed to complete this project. 4. Public health: A proper guidance of daytime napping (e.g. frequency and duration) depending on age will be proposed.