High blood pressure itself usually causes no symptoms, so it is easy to ignore. Left untreated, however, it can quietly damage your body for years. Eventually, it can lead to serious complications, such as heart attack, heart failure, stroke, kidney damage, and vision loss. Fortunately, lifestyle changes and medication can usually get blood pressure under control and reduce the risk of developing these problems.
Blood Vessel Complications
As times goes on, untreated high blood pressure can take a toll on blood vessels.
Healthy arteries have flexible walls that stretch like elastic. When the heart pumps blood through the arteries, their walls stretch to let it through more easily. But high blood pressure leads to overstretching, damaging cells in the arteries’ inner lining. This can set off a chain of events that makes the artery walls thick and stiff, a condition known as arteriosclerosis.
Overstretching can also cause tiny tears in blood vessel walls. These tears and the scar tissue they leave behind can catch debris in the blood, such as cholesterol. The result is a buildup of fatty deposits that narrow and clog the arteries, a condition known as atherosclerosis.
Trapped blood can form clots that further narrow a blood vessel and sometimes block it. Blood clots can also break off and travel through the bloodstream until they become lodged in a narrow blood vessel elsewhere in the body, causing trouble there. Depending on the site, blood clots sometimes lead to a heart attack or stroke.
Overstretching can create weak places in the arteries that bulge outward, a condition known as an aneurysm. If an aneurysm bursts, it can cause life-threatening internal bleeding.
High blood pressure that isn’t treated can damage the heart in several ways.
Coronary artery disease
When the arteries that supply blood to the heart become narrowed, blood can’t flow through them freely. This can cause chest pain (angina) or irregular heart rhythms (arrhythmias). Eventually, it may result in a heart attack.
A heart attack occurs when one of the arteries supplying blood to the heart becomes blocked by atherosclerosis or a blood clot. When this happens, the part of the heart supplied by the artery is deprived of nourishing blood, and that part of the heart begins to die. The longer the artery stays blocked, the worse the damage.
Left ventricular hypertrophy
Narrowed arteries force the heart to work harder to pump blood through the body. Just as lifting weights can make your biceps bigger, this added work can cause enlargement of the heart muscle in the left ventricle, the heart’s main pumping chamber. Enlargement and stiffening make it even more difficult for the ventricle to do its job.
Over time, the added strain on the heart can cause it to get weaker and work less efficiently. Eventually, the overwhelmed heart becomes unable to pump enough blood to meet the body’s demands, a condition known as heart failure.
Like other parts of the body, the brain depends on a healthy blood supply for nourishment. When high blood pressure isn’t controlled, the blood supply can be compromised.
A stroke occurs when part of the brain is deprived of the vital oxygen and nutrients in blood. Within minutes, brain cells begin to die. In the majority of cases, a blood clot blocks one of the arteries leading to the brain. In other cases, a blood vessel in the brain leaks or bursts, often due to high blood pressure or an aneurysm.
Dementia is a brain disorder characterized by impairments in memory, thinking, speaking and other mental skills. This form of dementia can be caused by a stroke or by reduced blood flow to the brain due to narrowed arteries there.
The kidneys’ job is to filter excess fluid and waste from the blood, and they depend on healthy blood vessels to do this efficiently. High blood pressure can damage blood vessels in and around the kidneys, causing serious problems.
Kidney failure refers to a loss of kidney function, which allows dangerous levels of fluid and waste to build up in the body. High blood pressure is a double threat. It can damage both the large arteries leading to the kidneys and the tiny blood vessels inside the kidneys.
The tiny blood vessels inside the eyes are delicate and vulnerable. When subjected to the force from high blood pressure, they may narrow or leak, leading to vision problems.
Hypertensive retinopathy refers to damage of the retina—the light-sensitive tissue at the back of the eyes—that is caused by high blood pressure. If blood pressure is not controlled, this can lead to vision loss or even blindness.
Many women with high blood pressure have healthy pregnancies. However, for others, uncontrolled blood pressure can cause problems. In pregnant women, it can damage the kidneys and other organs. In their babies, it can cause premature birth and low birth weight.
The most serious form of high blood pressure in pregnancy is preeclampsia. Although the exact cause is uncertain, blood vessel damage and insufficient blood flow to the uterus may play a role. In this condition, which typically begins after the 20th week of pregnancy, high blood pressure is combined with increased protein in the urine due to kidney problems. Most women with preeclampsia deliver healthy babies. However, the condition increases the risk for slow growth of the fetus, low birth weight, premature birth, and breathing problems as a newborn. In pregnant women, severe preeclampsia can also cause heavy bleeding, liver and kidney problems, or seizures—dangerous complications for both mother and child.
Male Sexual Complications
Men need healthy blood flow to achieve and sustain an erection.
Blood vessel damage can reduce the amount of blood that reaches the penis. For some men, the decreased blood flow interferes with their ability to have an erection, causing erectile dysfunction.