Help is appreciated. People with invisible illnesses often lead busy lives, including working, looking after family, and running active, busy households. An occasional offer of help, such as offering to run errands or cooking them a casserole will be greatly appreciated. Offer to be a point of contact should your friend suddenly need hospital treatment so you can support them. Ask them directly what you can do for them. What are the differences between ulcerative colitis and Crohn's disease? Find out here.