Environmental pollution with heavy metals is becoming a growing problem, which causes great concern about their potential harmful effects not only on the environment, but also on human health. Once heavy metals enter the environment, they can accumulate in soil, water and plants and are gradually transferred through the food chain. Metals as inorganic pollutants reach the environment due to the rapid growth of agriculture, especially due to the use of fertilizers and pesticides, as well as the metal processing industry, as well as improper disposal of waste. This paper shows how heavy metals enter the environment and what happens to them. Some types of heavy metals affect the biological functions and growth of organisms, while other metals accumulate in one or more organs, which can cause serious diseases. Heavy metals can cause a variety of health problems in humans, including damage to the liver, kidneys, nervous system, lungs and cardiovascular system. They can also be carcinogenic and have a negative impact on the reproductive system. The main goal of the work is to describe essential and non-essential heavy metals and their key properties and the sources from which they reach the environment.