It is surprising how people with really good intentions sometimes say really upsetting things. Many people I know with major health issues tell me about their frustration with the things that people sometimes say to them. Throughout my husband's illness the people in our lives usually said supportive, kind, and helpful things to us. However, I must say that I was surprised by the number of people who said things to us that were rather insensitive, thoughtless, or occasionally downright rude. Often these were well meaning friends and family members who would say something that was pretty much the last thing we wanted to hear. For example, it was quite common when people heard the news of his cancer diagnosis to immediately share the story of someone they knew who had died from cancer. This phenomenon isn't unique to cancer patients; most expectant mothers experience other women suddenly sharing their horror stories of complicated, painful, or otherwise difficult childbirth experiences. It is also common for people dealing with a medical issue to receive tons of unwelcome advice about a "better way" to treat their condition. All of this can add an extra dose of frustration to an already difficult time in your life. While every situation is different and every interaction is unique, there are a few things I've learned in handling this delicate and all too common situation.
Your first impulse when people say these things may be to "let them have it" and tell them that what they have said upsets, offends, or scares you. There is nothing wrong with doing this. If you are dealing with a major illness as a patient or caretaker your first priority always has to be to preserve your own mental well being. You only have so much mental and emotional energy and it's important to reserve that for your own health. So I believe it is fine to tell someone that what they have said is unhelpful. However I caution you to find a way to communicate this in a lighthearted way when possible. This is because almost always when people say these things they have good intentions and just aren't thinking.
What I have noticed is that most of the time when people say inappropriate things regarding a major illness it is usually because they are uncomfortable. Sometimes they are surprised to hear news of the illness and they can't think of what to say so they automatically think of a similar life situation and share about it. What they are really trying to say is "I'm familiar with this" or "I understand." However what sometimes comes out is something that is very unhelpful: a story that is discouraging or frightening. And other times the news triggers a strong memory for people. It is natural for them to then talk about the memory. The problem of course is that every patient and every situation is different so the sharing of other stories can be tedious or irrelevant even if the story has "a happy ending". Another way that people sometimes respond to the news is to share a solution or recommendation. This often comes from a strong desire to be helpful and to express support. Unfortunately it also often means they are sharing misinformation and/or unhelpful information because the person is not familiar with the patient's case.
To deal with these situations when they happen, I found it is helpful to have a few prepared responses, a sort of "stock answer" for the most common comments, questions, or stories shared. You may find it useful to connect with health professionals or other patients or caregivers who may be able to suggest some simple and succinct responses to the common things that people say when learning about your illness. For example many people told me or my husband that a sugar-free diet can cure cancer. This advice is based on a misinterpretation of data from a very old study. One of the oncology nurses explained to me why people believe this and why it won't work. When people would share this well-intentioned advice with me I would immediately thank them for the suggestion and then quickly explain the basic science of why it wouldn't help. And when people would begin to share stories of others they knew with cancer I would quickly cut in and lightly say "Oh don't tell me any scary stories about cancer, I like to focus on wellness." Most of the time people aren't upset if you do this, especially if it is a lighthearted tone. Usually they are looking to you for how to react to the news and are grateful for the guidance. Generally people want to say things that will make you feel better and will appreciate your cues on how to do that.
Unfortunately, sometimes you may have to face a difficult interaction with someone who is deliberately being rude. Sadly the personality conflicts and problems you experience in everyday life with others may not go away while you're dealing with an illness. Fortunately this is rare but occasionally people react to the illness of another by projecting their own emotional problems onto the patient or caretaker. For example a relative who always thought that the patient should go to church might tell the patient that they believe the patient wouldn't be ill if they went to church more often. This can happen with religion, dietary choices, or any other life choice you have made. If this happens, it is important to immediately tell this individual that their comments are unwelcome and that you will not tolerate hearing this type of communication. It is so important to reserve your mental strength for your well-being, and people who use the patient's illness as an opportunity to disparage their life choices should be kept at a distance. I recommend that the patient or caretaker enlist others, a close friend or family member, who can intercede and take the individual aside and explain the inappropriateness of their comments.
The thing to keep in mind as you navigate life while coping with illness is that mostly people just want to be as helpful and supportive as possible. People are human and they make mistakes just like you. So it is important to be as patient as you can while remembering that your mental well being takes precedence. It can be a delicate balance at times but I found preparing responses and seeking suggestions and advice from others can be immensely helpful in dealing with this particular challenge.