You have a condition called heart failure. When you have heart failure, a sudden weight gain or a steady rise in weight is a warning sign. It means that your body is retaining too much water and salt. This could mean your heart failure is getting worse. If left untreated, it can cause problems for your lungs and result in shortness of breath. Weighing yourself each day is the best way to know if you're retaining water. If your weight goes up quickly, call your doctor. You'll be given instructions on how to get rid of the excess water. You'll likely need medicines and have to avoid salt. This will help your heart work better.