The electrical activity of the heart is measured and recorded using an electrocardiogram, often known as an EKG or ECG, which is a basic diagnostic tool in cardiology. Electrodes are applied to the patient's skin during this non-invasive process in order to record the electrical impulses generated during the cardiac cycle. Cardiac arrhythmia signifies an abnormal heart rate or rhythm. When the heart beats too rapidly or irregularly, its pumping efficiency decreases, potentially reducing blood flow to the brain. This can lead to fainting, dizziness, or even death if not promptly addressed. The proposed health monitoring system is a comprehensive, portable solution designed to monitor key cardiovascular indicators—specifically, heart rate and blood oxygen saturation (SpO2)—in real-time. The system integrates two microcontrollers: an Arduino Mega and a NodeMCU. The Arduino Mega is responsible for displaying ECG waveforms on a TFT screen, as well as calculating and displaying the heart rate. This is achieved through an ECG sensor connected to the Arduino, which plots the heart's electrical activity on the display. A potentiometer allows users to set a customizable threshold line on the ECG waveform, which is used to count heartbeats. The heart rate is calculated based on the number of beats detected per second. If the heart rate falls below or rises above the normal range, the system alerts the user by displaying "Bradycardia" or "Tachycardia," respectively. Meanwhile, the NodeMCU module is connected to a MAX30100 sensor, which measures SpO2 levels. The sensor data is wirelessly transmitted to the Arduino Mega, where it is displayed on the TFT screen alongside the ECG data. This dual-functionality system not only provides continuous monitoring of vital signs but also offers immediate feedback on potential heart conditions, making it an essential tool for proactive health management.