It can be very difficult to predict the course of chronic illnesses such as chronic obstructive pulmonary disease (COPD) or congestive heart failure (CHF). Chronic illnesses place energy demands on the body that slowly deplete a person's energy reserve. In the later stages of illness, energy reserve is low, and seemingly small problems like a cold or infection can overwhelm a person's ability to fight it and a person's overall health and functioning change dramatically. This is often why a person's health seems to change suddenly.
 

Generally as the illness progresses, these sudden "flares" tend to happen more frequently. Interventions (such as using antibiotics to treat a suspected infection, or treating other problems suspected to be contributing to the situation) may help to improve the symptoms, and the person’s overall health and function. However, there is also the possibility that the person simply lacks the reserve energy to successfully overcome the illness, which leads to changes that signify the final days of life.
 

Because the path of chronic illness can be so unpredictable, it can be difficult to recognize the final phase of illness. This is partly because each flare-up tends to look much like the previous ones from which the person pulled through. The only clues that a flare-up is more serious may be a slower improvement with aggressive treatment, or tests that indicate other organs are weaker.
 

This uncertainty can be a concern for people and their families, and it can make decisions about investigations and treatment very difficult. Often in deciding how best to manage these symptoms, families and health care providers consider several things:
 

• The path of the illness to date
  Reviewing the big picture of what has happened in the past months can give an overall sense of how things are going. It can also help to clarify what kind of treatment a person might want in the future. For example, a person who has been hospitalized in the past may choose not to go to the hospital for future episodes. If this is the case, the team can then help to plan for other types of treatments (for example, medications) to treat worsening symptoms at home when they occur again.
  
   
• What is thought to be causing or contributing to the current situation? What are the potential benefits and burdens of further investigation and treatment?
  In situations where it is unclear if treatment will lead to improvement, a time-limited trial of treatment may be considered (for example, treating an infection with antibiotics for a given period). As part of such a trial, families and health providers usually talk about their hopes for the treatment and when benefits from treatment might be expected. For example, if symptoms do not improve within one week, this treatment has not been helpful and will be stopped.
   

Regardless of what treatment path is ultimately chosen, it is important to have the opportunity to discuss your options with a health care provider. Talking about what may be expected as the illness progresses, and having a plan, can help reduce feelings of uncertainty and anxiety. Planning for future symptoms can also help to ensure that the person is comfortable – regardless of whether the cause of the symptoms can be fixed.