Microplastics (MP) and nanoplastics (NP) are becoming an increasing global problem due to their high concentration and presence in all parts of the environment. If we consider the amount of plastic waste in the environment, which is large enough that the concentrations of MP and NP will only increase over time and that it is impossible to stop the production of plastics because they are currently irreplaceable material, it becomes clear how alarming the problem of environmental microplastic pollution is. It is therefore necessary to carry out a series of studies on the presence of MP in the environment and its impact on the environment and living organisms. This work provides an overview of the MP problem in terms of its occurrence in the environment, its transport and its effects on organisms with a focus on humans. The largest reservoirs of MP in the environment are oceans, fresh water, sediments, soil and air. MP enters the food chain and reaches the human organism as an end consumer through trophic transfer. Although MP has not yet been sufficiently researched, it has been shown that MP has negative effects on all living organisms including humans. A lot of knowledge is already available, but more needs to be discovered, so further research is needed for new solutions, regulations and laws.