Rare diseases and disabilities are often complex and very different in the severity and occurrence. They can be hereditary diseases, a variety of syndromes, progressive, debilitating or life threatening.
Rarity of a disease comes with challenges of disease identification, treatment, rehabilitation. The less common the disease, and the smaller the disability group, the more challenging it becomes to find expert knowledge or empirical peer support
There are an estimated 6000 to 8000 different rare diseases in Finland. A disease is considered rare, in Finland, when there are a maximum of 2,700 people suffering from it.