Answer:
Sometimes it just happens. But usually it’s left-side heart failure that causes right-side heart failure. As the left chamber of the heart loses some of its ability to pump, blood continues to back up -- sometimes into the lungs.
Heart failure is a long-term condition that gets worse over time. In most cases, it occurs due to other health issues that have damaged or weakened the heart.
Step-by-step explanation:
Right-side vs. Left-side Heart Failure
When the heart is working normally, it pumps oxygen-rich blood through lungs and to the rest of the body. The left ventricle, or left chamber, of the heart provides most of the heart’s pumping power. So, when someone has left-side heart failure, their heart can’t pump enough blood to their body.
The right ventricle, or right chamber, moves “used” blood from the heart back to the lungs to be resupplied with oxygen.
So, when someone have right-side heart failure, the right chamber has lost its ability to pump. That means their heart can’t fill with enough blood, and the blood backs up into the veins. If that happens, their legs, ankles, and belly often swell.