Psoriasis is a skin condition that causes red, flaky, crusty patches of skin covered with silvery scales.
These patches normally appear on your elbows, knees, scalp and lower back, but can appear anywhere on your body. Most people are only affected with small patches. In some cases, the patches can be itchy or sore.
Psoriasis affects around 2% of people in the UK. It can start at any age but most often develops in adults under 35 years old, and affects men and women equally.
The severity of psoriasis varies greatly from person to person. For some it's just a minor irritation but, for others, it can majorly affect their quality of life.
Psoriasis is a long-lasting (chronic) disease that usually involves periods when you have no symptoms or mild symptoms, followed by periods when symptoms are more severe.
Read more about the symptoms of psoriasis.