What you can do: Psychologist Alice Chang, coauthor of A Survivor's Guide to Breast Cancer, says that if a friend is ill but mobile, you should take her out to eat every week or two, because sick people are often isolated. If she's housebound, drop off some food, and bring videos and books on tape, because certain treatments impair vision. "Don't overstay your visit," she says. "Acknowledge the illness and ask what the progress is, and then talk about activities of daily living." If she's a close friend, volunteer to do laundry or clean her house, chores she may be unable to do herself. And be sensitive to the pendulum swings of her mood. Chang says, "I tell people, 'I know that the feelings are not always rational, because that's how emotions are. But it's okay.'"

What you can say: Don't blurt out that she looks awful, but don't tell her she looks great if it's clearly not true. "Hug the person and say, 'Some days are better than others, and I hope you have more better days,'" says Chang. If her appearance has radically changed—if she's bald from chemo, for instance—don't pretend you don't notice. "Instead," Chang recommends, "say, 'You have a nicely shaped head' or 'Isn't it a lot cooler?'"

What to avoid: Don't say, "I know how you feel." An epileptic patient once told Chang, "If I've heard it once, I've heard it a thousand times—'I had a dog with epilepsy, so I know how you feel.'" The truth is, you don't know how your friend feels, so the best approach is to invite her to tell you.

From the August 2006 issue of O, The Oprah Magazine