Water & High Blood Pressure

High blood pressure affects one out of every three Americans, according to the American Heart Association. Regardless of a person's health, the body attempts to use different mechanisms for controlling and regulating blood pressure levels. One of the ways it does this is by adjusting the levels of water in the bloodstream and tissues.

Blood Pressure

• The body's circulatory system is composed of blood vessels and the heart, which pumps blood throughout the body to deliver needed oxygen supplies to cells, muscles and organs. Each time the heart beats, it exerts a certain amount of pressure on blood vessels, which respond to the heartbeat by dilating, or expanding, so blood supplies can flow through. Between heartbeats the blood vessels generate a certain amount of pressure as blood flows through them. According to the Merck Manual, water levels in the bloodstream can increase when the heart requires more pressure to move blood through the body.

Controls

• The sympathetic nervous system and kidneys work together to regulate blood pressure levels in the body, according to the Merck Manual. Increases in blood flow during times of stress or heavy exertion are designed to push blood through at a faster rate. To do this, either the heart has to work harder or the blood vessels have to expand and contract in such a way as to push blood through quickly. The kidneys can also help increase pressure levels by sending water into the bloodstream, increasing blood volume. When this happens, blood pressure increases as well.

Effects

• High blood pressure over long periods can cause significant damage along the blood vessels and also weaken the heart muscle, according to the American Heart Association. This can cause blood vessel walls to develop scarring, causing a loss of elasticity. Under normal conditions, the kidneys will begin to excrete water and salt out of the body, thereby lowering blood volume levels, according to the Merck Manual. If blood vessels have suffered considerable damage, systems in the body may begin to break down, as adequate oxygen supplies are not being met. When this happens, the kidneys may be unable to respond appropriately.

Diuretics

• Diuretics are medications used to reduce the amount of water in the body. They're often used to treat fluid buildup in body tissues that develop when cells contain excess salt. When this happens, the sympathetic nervous system can become overly sensitive, causing the kidneys to release excess amounts of water into the bloodstream. According to the American Heart Association, diuretics help to reduce water amounts by causing the kidneys to remove more water and salt than usual from the bloodstream.

Considerations

• While diuretics can help in the treatment of high blood pressure, it can be difficult for doctors to determine how much excess water is in the body, according to the American Heart Association. Removing too much water can cause blood pressure levels to drop below normal, producing fatigue and impairing normal kidney function. Diuretics can also alter normal potassium levels in the body, thereby affecting energy levels. As a result, individuals prescribed diuretics are often advised to monitor their weight to prevent excess water loss.