Misunderstandings are common when terminal illness and prognosis are discussed. Most people, including some healthcare providers, are uncomfortable with the subject. Because of this, or because they want to prevent distress, health providers may use vague terms that are open to interpretation. Two people can be using the same words, but be talking about different things.

For example, the word "prognosis" can have different meanings. It’s possible that a physician uses the word to mean one thing, such as chance of cure, while you may be thinking about something else, such as your father’s life expectancy or quality of life.

Some healthcare providers don’t like to predict life expectancy because it’s difficult to estimate and rarely accurate. At early stages of an illness, forecasts are based on published studies. As the illness progresses, such studies become less relevant. There are so many factors that come together to influence a person’s health. This is why one person’s experience can be very different from another person’s experience, even if they are both confronting similar illnesses. Even so, it’s reasonable to ask if your father’s life expectancy can be measured in days, weeks, or months.

A guide used by palliative care providers is something called the momentum of change. When someone’s condition changes from one month to the next, there may be months of life left. Changes from week to week can mean weeks left. Eventually, your father’s energy and strength will decrease until he’s spending most of his time in bed. His condition may change from day to day and then hour to hour, at which point, he likely has days then hours of life left. This is a guide only, as something may happen unexpectedly.

It helps to remain hopeful, but plan for even the worst possibility. If you or your father need to address some matters, then now is good time to do it, while your father is still able. People often wait too long to tie up financial and other affairs, or to connect with other loved ones.

Families and patients vary greatly in how much they want to know. Healthcare providers may not be sure how much detail to give, and may look to you for cues. You can help by being clear about how much information you wish to have.