SN explain about congestive heart failure ( CHF ). As blood flow out of the heart slows, blood returning to the heart through the veins backs up, causing fluid to build up in the tissues. The kidneys are less able to dispose of sodium and water, also causing fluid retention in the tissues. Fatigue, a tired feeling all the time and difficulty with everyday activities, such as shopping, climbing stairs, carrying groceries or walking. The heart can't pump enough blood to meet the needs of body tissues. The body diverts blood away from less vital organs, particularly muscles in the limbs, and sends it to the heart and brain. Lack of appetite, nausea, a feeling of being full or sick to your stomach. The digestive system receives less blood, causing problems with digestion. Confusion, impaired thinking, memory loss and feelings of disorientation. A caregiver or relative may notice this first. Changing levels of certain substances in the blood, such as sodium, can cause confusion. If you have 2 or more of these symptoms you may need to seek medical attention.