Public debt has increased significantly in most countries in the last 3 years as a result of the global crisis that has begun in 2020 in the context of the outburst of covid-19, and of the effects of the measures adopted by the authorities in order to stop the spread of the disease. In this context, the author aims to analyze what is the level of debt beyond which it is no longer sustainable, and it becomes a burden for the debtor economy, as well as the factors that influence this level. The article1 explains what the debt threshold is. Next, it is shown, based on economic literature, the elements that exert influence on debt thresholds, but also what are the factors on which depend the effects of public debt on economic growth. The notion of debt threshold is used by some researchers to describe a level of debt to GDP beyond which debt no longer supports economic growth, but it has negative effects on economic growth. The methodology used consists of comparative and descriptive analyses, literature review.