The article reviews the advancements in microneedle sensors for point-of-care (POC) diagnostics, emphasizing their potential in personalized medicine. Microneedle sensors, which provide direct and painless access to biomarkers from interstitial fluid (ISF), have gained significant attention due to their ability to perform blood-based diagnostics. The review highlights the integration of electrochemical and optical sensing techniques in various "lab-on-a-microneedle" platforms, with microneedles constructed from metals, inorganics, polymers, and hydrogels. These sensors can detect a wide range of biomarkers, including electrolytes, metabolites, nucleic acids, proteins, and drugs. The article also discusses the fabrication techniques for microneedles, such as formative, subtractive, and additive manufacturing methods, and the biological matrices accessed by microneedles, including blood, ISF, cells, and tissues. Additionally, it covers the construction of microneedles for sensors and diagnosis, focusing on the materials used, their mechanical properties, and their applications in various diagnostic scenarios. The review concludes by outlining the future prospects of microneedle sensors in advancing personalized and intelligent health management.The article reviews the advancements in microneedle sensors for point-of-care (POC) diagnostics, emphasizing their potential in personalized medicine. Microneedle sensors, which provide direct and painless access to biomarkers from interstitial fluid (ISF), have gained significant attention due to their ability to perform blood-based diagnostics. The review highlights the integration of electrochemical and optical sensing techniques in various "lab-on-a-microneedle" platforms, with microneedles constructed from metals, inorganics, polymers, and hydrogels. These sensors can detect a wide range of biomarkers, including electrolytes, metabolites, nucleic acids, proteins, and drugs. The article also discusses the fabrication techniques for microneedles, such as formative, subtractive, and additive manufacturing methods, and the biological matrices accessed by microneedles, including blood, ISF, cells, and tissues. Additionally, it covers the construction of microneedles for sensors and diagnosis, focusing on the materials used, their mechanical properties, and their applications in various diagnostic scenarios. The review concludes by outlining the future prospects of microneedle sensors in advancing personalized and intelligent health management.