A sudden (acute) episode of
heart failure is most often the result of heart
function that gets worse. You may become much more short of breath, have much
more fluid buildup (edema) than usual, and find that your ability to exert
yourself is significantly reduced. If the episode is very severe, you may also
develop symptoms of low cardiac output such as lightheadedness, profound
fatigue, or decreased urine output. What sets an acute flare-up apart from the
expected gradual worsening of your heart failure over time is that the change
in symptoms occurs over a very short time.
Acute episodes of heart failure are very common and are one of the
most common causes of admission to the hospital. What happens after one of
these flare-ups depends on the cause. It is likely that your heart failure
symptoms will return to their prior baseline once the cause is treated if it
was caused by a temporary situation such as a high-salt meal, forgetting your
medicines, or developing an irregular heartbeat (specifically, atrial
fibrillation), anemia, an infection, or a fever.