All living cells respond to sudden, adverse changes in their environment by evoking a stress response. Here we focus mainly on the response of the model eukaryotic organism Saccharomyces cerevisiae (baker's yeast) to an increase in external osmolarity. We summarize data demonstrating that stress responses largely depend on the existing environmental growth conditions. Nutrients and other medium parameters such as external pH determine how yeast cells sense osmotic stress circumstances and subsequently elicit adaptive responses. It is likely that the composition of cell wall and plasma membrane plays an important role in this process.