Dear Doctors: I'm 74 years old, and I was diagnosed with advanced congestive heart failure. I take a diuretic and a heart failure medication. With moderate cardio therapy and the medications, my thirst runs rampant in the evening. When I drink fluids, am I nullifying the intent of the diuretics?
Dear Reader: At the core of your question is the management of fluid balance. This is one of the more challenging aspects of treating congestive heart failure. It is a complex issue that involves multiple interconnected processes in the body. Approaches are different for everyone, which is why we can't give advice. What we can do, though, is explore how congestive heart failure affects the body and the reasons managing fluids becomes so important. We hope to give you useful information for when you talk with your cardiologist.
Congestive heart failure, or CHF, is a condition where the heart can no longer pump blood well enough to meet the body's needs. In the early stages, symptoms can be subtle. These include shortness of breath, fatigue and mild ankle swelling. The symptoms are often triggered by physical activity. As the condition advances, fatigue or exhaustion can happen at rest. Breathing gets difficult, and swelling in the limbs gets worse.
When the heart can no longer work well, the amount of blood it sends out decreases. Blood returning to the heart backs up in the veins. This results in an increase in pressure within the blood vessels. Fluid begins to leak into nearby tissues. That same reduction in blood flow also affects the kidneys. It triggers mechanisms that cause the body to retain sodium and water. All of this leads to a systemic buildup of fluid known as congestion. That’s where this form of heart disease gets its name.
This buildup of fluid in the tissues is known as edema. It is often most visible in the lower extremities, where swelling can range from mild to severe. Fluid can also build up in the lungs. Known as pulmonary edema, this can cause serious breathing problems. The diuretic and the specific CHF medication you are taking both increase the amount of fluid you lose in urine. However, they do so through different mechanisms, which makes the issue more complex.
Drinking an appropriate amount of fluid does not cancel out the effects of either drug, but if you drink too much, it can contribute to fluid buildup. Drinking too little can also cause problems. It can lead to dehydration, low blood pressure or electrolytes getting out of balance. This makes it important to discuss your persistent thirst with your cardiologist. The real question is not how much you should drink, but what is causing your thirst. Persistent or excessive thirst can be a symptom of diabetes. So, it's important to alert your doctor. They can order tests and review your medications and exercise routine. The goal is an optimal balance for comfort and safety.
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