The integration of the Internet of Things (IoT) in healthcare has the potential to revolutionize patient monitoring. Yet, challenges such as high costs, limited accessibility, data privacy, security, and accuracy of sensor integration persist. This paper presents the design and implementation of a cost-effective IoT-based health monitoring system addressing these issues. The system utilizes an ESP32 microcontroller, integrated with a thermal sensor, pulse oximeter, heart rate sensor, and a temperature and humidity sensor to monitor patient’s body temperature, oxygen saturation [saturation of peripheral oxygen (SpO2)], heart rate, and environmental conditions. Sensor data is displayed locally on an OLED screen and transmitted wirelessly to a cloud server (ThingSpeak) using the Hypertext Transfer Protocol (HTTP) protocol, enabling real-time remote access and secure data storage. The system achieves high accuracy of 99.435%, 99.381%, and 99.325%, respectively, for body temperature, SpO2, and BPM, with relative errors of 0.565% for body temperature, 0.619% for SpO2, and 0.675% for BPM. A sophisticated user interface with tactile switches enables users to pick and validate patient profiles to efficiently monitor patient data locally. With a production cost of approximately $13, this portable system offers affordability and practicality, particularly for underserved regions and telemedicine applications. Compared to prior systems, it combines enhanced accuracy, real-time cloud integration, and user-friendly interfaces at a lower cost. Its potential to improve patient care through continuous monitoring and remote accessibility establishes it as a scalable solution for modern healthcare challenges.