It is very important to keep careful track of your weight because it is one of the best indicators of the fluid accumulation that usually happens with heart failure. It isn't perfect since fluid is not the only thing that effects your weight, but there are several things you can do to make it a better indicator. First, always weigh yourself at the same time relative to meals and after bowel or bladder movements. Usually the best time is just after getting up in the morning after going to the bathroom. Second, weigh yourself without clothes. Wearing the same clothes is alright, but flannel pajammas can easily be a pound heavier than light-weight ones. Third, use a good scale, most importantly, one that is consistent, since we are looking for changes. One pound resolution (or half a kilogram) is adequate.
Weigh yourself daily! How rapid the change occurs helps to determine what caused it. If you don't have a chance to interact with the program, write the weights down and enter them all the next time you use the program.
If you enter a weight that represents a change, the program will ask you about possible reasons to narrow down what might be happening.