Rare diseases is a new concept in the field of medicine. At the level of the EU, awareness of the challenges posed by rare diseases began to grow at the beginning of the 21st century.
When speaking about the health of the population, the focus is usually on common diseases. Rare diseases are the opposite of common diseases. A disease is classified as rare when it affects fewer than one in 2,000 people, but many diseases are much rarer than that. Altogether, they affect 6-8 percent of the population.
