One in three people suffer from stress on a regular basis and just under a half claim to frequently take prescription medication.
The Red C research found that the number of Irish adults who drink alcohol regularly stands at 38% - much higher than the world average of 19%.
34% of people said they suffered from stress fairly or very often, with women in younger age groups and those living in Munster claiming to have the highest stress levels.
Two in five people say they don't sleep well, while those who admit to smoking frequently stands at 17% - slightly lower than the global average of 20%.
With regards dieting, 17% of people claimed to be regularly watching what they ate, with women more likely than men to do so.
Overall, Irish people were found to be near the bottom of the pile when it came to fitness and in the bottom half when it came to body weight and mood.
The research was carried out as part of the 2018 WIN World Survey, which looked at the views and beliefs of 31,000 people from 40 countries worldwide.
Despite the findings, 83% of adults perceive their health as good or very good, according to data released by Eurostat yesterday, meaning Irish people consider themselves to be the healthiest in the European Union.