Protein misfolding, which include the formation of amyloid aggregates, insoluble aggregates resistant to degradation, are related to a large number of different diseases, mostly neurodegenerative. In this work, hen egg white lysozyme has been used as model because it is a good characterized protein with ability to form this kind of aggregates if it is exposed to extreme conditions. Usually, the in vitro studies are done in a diluted medium, and the action of the protein at these concentrations differs from what happens inside the cell, mainly because the internal concentration is crowded by numerous macromolecules. The purpose of this research is to study what occurs if a protein forms amyloid aggregates in a crowded medium made by different agents (Dextran 40, Dextran 70 and Ficol 70) at different crowder concentrations (5%, 10% and 20%). In order to characterize what happens with lysozyme when it is forced to form this kind of aggregates, infrared spectroscopy has been used not only because it is a useful technique for this kind of studies, but also due to the fact that analysis time is short. Moreover, little quantity of protein is needed and also the technique has a high sensitivity to β structures which are characteristic of amyloid fibers. As it is shown, lysozyme aggregates are formed different in a diluted medium or in a crowded one because the fiber quantity formed decreases, and the kinetic formation differs. These changes arise from the different effect of crowders at distinct concentrations.