Intensive Care Unit or ICU is where the patients who are critically ill and admitted for treatment. For such critical conditions the Doctors need to have an all-time update patients health related parameters like their blood pressure, heart pulse ,temperature Asthma, Environment and saline is full or not. Doing manually is too tedious a task and also for multiple patients it becomes close to impossible. For this type of situations this IoT based system can bring about an automation that can keep the doctors updated all time over the network. IoT Based ICU Monitoring System is an Arduino based system which collects patients information with the help of few sensors. The sensors which are networked, either worn on the patient's body or embedded in our living environments, change the gathering of data inductive of our physical and psychological state. Internet of Things (IoT) based smart health monitoring system is a patient monitoring system in which a patient can be monitored 24 hours. In the present world Health monitoring systems are one of the most notable applications of IoT. In ICU, patient monitoring is critical and most important activity, as small delay in decision related to patients' treatment may cause permanent disability or even death. Most of ICU devices are equipped with various sensors to measure health parameters, but to monitor it all the time is still challenging job.We are proposing IoT based system, which can help to fast communication and identifying emergency and initiate communication with doctors and also helps to initiate proactive and quick treatment. This health care system reduces possibility of human errors, delay in communication and helps doctor to spare more time in decision with accurate observations. The proposed system here consists of various sensors and mobile based applications which communicate via connected devices and helps to monitor and record patients' health data and medical information. This paper proposes a smart healthcare system in IoT environment that can monitor a patient's basic health signs as well as the room condition where the patients are now in real-time. The purpose of this study is to suggest an IoT design for smart monitoring and emergency alert system for patients in ICU which will monitor a patient using sensors. In this system, five sensors are used to capture the data from hospital environment named EMG sensor ,ECG sensor,LM35 Thermister sensor, Humidity sensor DHT-11 and Load Cell. Arduino Uno Controller which will gather information from the patient and send to the IoT server. The sensor value crossed threshold values. If there is any sudden change in the health condition of the patient who are using this health care system module, automatically the data of the patient will be uploaded to the concerned doctor, within few minutes user will get a prescription for his current situation The condition of the patients is conveyed via a LCD to Doctor, where they can process and analyze the current situation of the patients. Smart ICU are designed to use i...