World Sickle Cell Day: What not to say to people with invisible conditions
Today is World Sickle Cell Day. Sickle cell is an invisible condition, which means that you might not know that somebody has it just by looking at them.
George, Maisie, Amiyah, Ayshin, Chloe and Bridget - who all have invisible conditions - told Newsround about the things people who don't understand what life with their condition is like say to them, and how that can be frustrating.