They often suffer in silence.
Acutely aware that others may not want to hear about their pain, many people with chronic illnesses will suffer their hardships quietly. They may miss social engagements because they are too ill to attend, but will downplay their non-attendance.
They become very good at pretending to be well and often don’t look ill. This may be because they have made an extra effort with their appearance to mask how they really feel, or they are managing their symptoms with medication so they can get through the day.
They have a different take on life.
When you’re faced with a chronic illness and possibly your own mortality, you tend to place importance on different things. They will jump at new opportunities, try not to put things off until tomorrow or sweat the small stuff, and enjoy the simple pleasures in life.