I know to well the fret and worry of elderly family members. My paternal grandparents are both 83 years old now, coming up on year 84. They've been married for 61 years and have had 6 kids, 3 of which were identical female triplets.
They aren't as young as they used to be, yet still are living on the family farm. The same one on which Grandpa was born. In fact, he may die on that farm if they don't move to town one of these days, into an apartment complex. Grandma keeps talking about moving there some day, but nothing is ever done.
They are both as stubborn as they come and still insist of helping out my Uncle, there son, who also lives on and now manages the family farm. Grandma has lupus, which while its in remission for now, could flare up unexpectedly. She has to stay out of the sun as much as possible as she is now photosensitive.
Lupus is an autoimmune disorder, where, for some reason, the immune cells attack healthy tissue instead of diseased tissue, like they are supposed to.
Grandpa, on the other hand, once had lymphatic cancer/Hodgkin's lymphoma. It was mostly in the lymph nodes in his cheek and neck. He underwent radiation and steroidal therapy and thankfully, the cancer receded and he didn't need his lymph nodes surgically removed. He is now cancer free.
Ironically, his battle with cancer happened at the same time my kid brother was battling Acute Lymphatic Leukemia. My brother is now cancer free, and would be healthy, if he didn't smoke and drink so darned much.