The heart can be compared to a four room apartment or a house. An apartment has doors between rooms, so does the heart have valves. Just like doors, the valves open in a certain direction when blood flows through them.If the heart valves open in the reverse direction and blood flows in a reverse direction, it is a sign of heart disease. In an apartment we may freely move to any room, but the blood in our heart can move only in a predefined direction, between predefined chambers. If the blood flows into the wrong direction and in the wrong chambers, that could be a sign of heart disease too. Lastly, the rooms in an apartment have walls. The chambers of our heart also have walls. Rarely, these walls may have openings or weakness in them, another sign of heart disease.