Patients with heart failure often have a tendency to retain salt and water in the body and in the blood circulation. This can lead to an additional burden on the heart with accumulation of fluid in the lungs, increased shortness of breath and/or swelling of the feet and/or legs.
That is why it is often recommended not to drink too much. This is especially important for patients who need to take water pills (water tablets, diuretics). In these patients, drinking too much may lead to the need for a higher dose of diuretics and therefore a need to urinate more.
For patients who should not take diuretics, this advice is less strict as long as there are no signs that the body is retaining fluid (increasing weight, increasing shortness of breath, swelling of the lower legs).