4 doctors weighed in:
How does CHF cause pleural effusion?
4 doctors weighed in

Dr. William Walsh
Addiction Medicine
2 doctors agree
In brief: Leaky lungs
The pulmonary lymphatic system can hold about 4 liters of fluid per lung (8 liters total) before they start to leak.
In heart failure, there is back pressure from the left side of the heart into the lungs; if there is enough pressure to result in more than 4 liters backing up on one side, the lungs will leak into the pleural space leading to an effusion.

In brief: Leaky lungs
The pulmonary lymphatic system can hold about 4 liters of fluid per lung (8 liters total) before they start to leak.
In heart failure, there is back pressure from the left side of the heart into the lungs; if there is enough pressure to result in more than 4 liters backing up on one side, the lungs will leak into the pleural space leading to an effusion.
Dr. William Walsh
Dr. William Walsh
Thank
Dr. Bennett Werner
Internal Medicine - Cardiology
In brief: Complex mechanism
When both ventricles fail (& it does require both), there is hydrostatic back pressure in the pleural and pulmonary vascular beds causing transudation of fluid from the vascular compartment to the interstitial space.
Moreover, hormones are secreted such as aldosterone which act on the kidneys to retain fluid and engorge the central circulation: nature's way of attempting to improve cardiac output.

In brief: Complex mechanism
When both ventricles fail (& it does require both), there is hydrostatic back pressure in the pleural and pulmonary vascular beds causing transudation of fluid from the vascular compartment to the interstitial space.
Moreover, hormones are secreted such as aldosterone which act on the kidneys to retain fluid and engorge the central circulation: nature's way of attempting to improve cardiac output.
Dr. Bennett Werner
Dr. Bennett Werner
Thank
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