Fluid control complications include delivering too much fluid too quickly, resulting in fluid overload. Alternatively, insufficient fluid may be administered, or it may be supplied too slowly. Overload can result in headaches, high blood pressure, anxiety, and difficulty breathing. It can also lead to more serious problems such as heart failure or kidney damage. If you receive too much fluid, your body will try to eliminate the excess by re-absorbing some of the water into your bloodstream. The kidneys are very efficient at this process; therefore, any patient who has received a large amount of fluid may appear thirsty, even though they are not drinking anything. The only way to tell for sure if you have received an excessive amount of fluid is if your pulse increases while you're lying down. If so, you should consider reducing the amount of fluid you're receiving. IV fluids that are delivered directly into a vein (intravenously) instead of through a stomach tube (enteral) are called "central venous lines" and are placed by doctors who specialize in cardiac care. These lines provide access to the circulatory system for delivery of medications, nutrition, and other treatments. Central venous lines also provide a safe way to give patients blood products if they are going to be returned to the blood pool (such as with transfusions). The most common complication of central venous lines is infection.