Stay vaccinated (or don't go out if you're sick).

People with compromised immune systems may be especially sensitive to sickness. If you leave the house while sick, you risk getting somebody else sick who may face more serious symptoms or even cause death. Additionally, many people with chronic illnesses are physically unable to get vaccinated due to certain natures of their condition. They can't be protected from diseases as you can. If you don't get vaccinated and contract something, it may be passed on to chronic patients. If you must leave the house while sick, wash your hands, wear a mask, and stay away from people who you know have compromised immune systems.

Don't make lifestyle assumptions.

People with chronic illnesses usually have to adhere to strict lifestyles in order to stay healthy. It can feel isolating when a chronic patient is presented with a situation in which they can't participate, but aren't given an 'out.' Most people with chronic illnesses don't want to use their condition as an 'excuse' or for a means of receiving attention, and therefore are uncomfortable bringing it up around new people. So, let's always make sure we factor in other people's abilities before setting up a possibly exclusionary situation. You can never tell if someone has a chronic illness, so just expect that everyone does.

When you ask someone to do something with you involving food or activity, present it as an option. Instead of saying, "let's get ice cream," ask, "if you want, we should go get ice cream. Or, is there another snack you'd like?" It is then much easier for the person to answer with, "I can't eat ice cream, could we get coffee?" Or, instead of saying, "let's walk to the store," ask "are you okay with walking to the store? We can get an uber or a bus instead." It is then much easier for the person to answer with, "I don't think I can walk that far. I'll call an uber."

There a million situations I could use as an example, but you get the idea.

Educate, but don't pry.

If you have a question about chronic illness, ask it. Chronic patients want you to find out more about their experiences. It shows you care. If you pose the question as a curiosity, and not as a means to dig into their life, we will always be okay with it!

Always provide more than one option. 

When setting up anything (from dinners to events, to a lecture, etc.) plan for out-of-the-ordinary needs. People with chronic illnesses often require certain food, accessibility, medicines, etc. Please either ask beforehand or prepare for those accommodations. For example, when planning lunches for a large group of people, provide a few different options (you can rarely go wrong with a vegetable-based, no carb, no sugar, no dairy meal), plan for extra table space for wheel-chairs, canes, walkers, etc. and make sure that facilities such as bathrooms are easily accessible and available at all times.

Donate if you can.

Chronic illnesses are exorbitantly expensive, especially since most insurance companies don't cover their treatment. Donations can help patients pay for their medical bills, but they can also help fund research and other studies. However, be careful where you donate, as many organizations don't actually properly help patients and use the money to incorrectly diagnose and treat people. If you want to donate, I recommend donating to ILADS (a Lyme Disease organization), it's reputable and trustworthy. If you want to help with other illnesses, I highly encourage it, just make sure you do your research.