:: Disease Information ::

There are two main types of high blood pressure. Primary or Essential Hypertension and Secondary Hypertension.

Primary Hypertension: Most people with high blood pressure - 95% - have what's called primary or essential hypertension. This means that there's no single clear cause of it.
Although there is no specific cause of essential hypertension, But you are also more likely to develop hypertension if you:

are obese (very overweight)
drink a lot of alcohol
eat a lot of salt
are under a lot of stress
have stron family history.

Secondary hypertension
You may be among the other 5% of people with high blood pressure who have what's known as secondary hypertension. This means your condition can be linked to a recognised cause - in fact, it may be a symptom of another underlying disease.
Secondary hypertension can be caused by:

kidney disease
adrenal gland disease
narrowing of the aorta (Coarctation)
Secondary hypertension can also be caused by the contraceptive pill (rarely), steroids, or by pregnancy causing pre-eclampsi

RISK FACTORS

Are overweight
Are a man over the age of 45
Are a woman over the age of 55
Have a family history of high blood pressure
Have prehypertension (that is, blood pressure in the 120–139/80–89 mmHg range)

Eating too much salt
Drinking too much alcohol
Not getting enough potassium in your diet
Not doing enough physical activity
Taking certain medicines
Having long-lasting stress
Smoking (smoking can cause a temporary rise in blood pressure)

SMOKING & HIGH BLOOD PRESSURE

How does smoking affects blood pressure?
One study says that smoking decreases blood pressure because smoking causes anorexia and person who smokes eat less so his or her weight decreases, so the blood pressure decreases.

How blood pressure is increased by Smoking?
Smoking injures blood vessel walls and speeds up the process of hardening of the arteries (Atherosclerosis). So even though it does not cause high blood pressure, smoking is bad for anyone, especially those with high blood pressure. If you smoke, quit. If you don't smoke, don't start. Once you quit, your risk of having a heart attack is reduced after the first year. So you have a lot to gain by quitting.

Moreover, the nicotine in cigarettes and other tobacco products causes your blood vessels to constrict and your heart to beat faster, which temporarily raises your blood pressure. If you quit smoking or using other tobacco products, you can significantly lower your risk of heart disease and heart attack, as well as help lower your blood pressure.

Whether tobacco is smoked, chewed, or taken in by any other means, the nicotine in the tobacco raises the blood pressure. The more you smoke, the higher the nicotine level is in your blood, and the higher your blood pressure. This accounts to a large extent for the great increase in brain attacks, heart attacks, and pain in the legs due to poor circulation (Claudication) in smokers, sometimes leading to amputation.

Nicotine raises your blood pressure by constricting your blood vessels. This occurs because the oxygen in your blood decreases and because nicotine directly stimulates the production of a hormone, epinephrine (also known as adrenaline), in the adrenal gland. Epinephrine raises blood pressure by constricting blood vessels. After tobacco use raises blood pressure, you’re at risk of all the medical consequences of high blood pressure, not to mention diseases associated with smoking, such as mouth and lung cancer.

Numerous studies have shown that smoking or chewing tobacco raises blood pressure and that when you stop using tobacco products, your blood pressure falls. The latest such study in the Journal of Hypertension (February 2002) comes from France. Out of 12,417 men who were current smokers, previous smokers, and never smokers, current smokers had the highest prevalence of high blood pressure. Previous smokers had a lower prevalence with the highest rate of high blood pressure in those who had recently stopped and had smoked for the longest time. Those who had never started smoking had the lowest prevalence of high blood pressure.

Smoking affects blood pressure by following means :
1. Smoking can lead to the build-up of plaque that clogs the blood vessels that supply the heart with blood.
2. When you smoke, you inhale carbon monoxide. This decreases the amount of oxygen your heart, brain, and other vital organs receive.
3. Smoking (Nicotine Produces epinepherine) constricts blood vessels.
4. Smoking damages the linings of blood vessels and speeds up the process of atherosclerosis.

HYPERTENSION DURING PREGNANCY

Up to 5 percent of women have hypertension before they become pregnant. This is called chronic hypertension. Another 5 to 8 percent develop hypertension during pregnancy. This is referred to as gestational hypertension. Gestational hypertension generally goes away soon after delivery; however, women who develop it may be at increased risk of developing hypertension later in life.

High blood pressure usually causes no noticeable symptoms, whether or not a woman is pregnant. However, hypertension during pregnancy can cause serious complications for mother and baby. Fortunately, serious problems usually can be prevented with proper prenatal care.
What is gestational hypertension?
There are two main forms of gestational hypertension. Both occur after the 20th week of pregnancy and go away without treatment soon after delivery. Preeclampsia is a potentially serious disorder, which is characterized by high blood pressure and protein in the urine. When high blood pressure is not accompanied by protein in the urine, it is referred to as gestational hypertension. However, gestational hypertension may progress to preeclampsia, so all women who develop high blood pressure in pregnancy are monitored closely.

Preeclampsia also may be accompanied by swelling (edema) of the hands and face and sudden weight gain (5 or more pounds in one week). Other signs of preeclampsia include blurred vision, severe headaches, dizziness and intense stomach pain. A pregnant woman should contact her health care provider right away if she develops any of these symptoms.

Preeclampsia usually occurs after about 30 weeks of pregnancy. Most cases are mild, with blood pressure around 140/90. Women with mild preeclampsia often have no obvious symptoms. If left untreated, though, preeclampsia can cause serious problems.

It’s important to remember that many women who develop preeclampsia or gestational hypertension do so at term (at or beyond 37 weeks of gestation). These women generally have few complications.

What risks do preeclampsia and other forms of hypertension pose for a pregnant woman and her fetus?
All forms of hypertension can constrict the blood vessels in the uterus that supply the fetus with oxygen and nutrients. When this occurs before term, it can slow the fetus’s growth, sometimes resulting in low birthweight. Hypertension also increases the risk of pretermdelivery (before 37 weeks gestation). Premature and low-birthweight babies face an increased risk of health problems during the newborn period and lasting disabilities, such as learning problems and cerebral palsy.

Women with hypertension also have an increased risk of placental abruption, which is separation of the placenta from the uterine wall before delivery. Severe abruption can cause heavy bleeding and shock, which are dangerous for both mother and baby. The most common symptom of abruption is vaginal bleeding after 20 weeks of pregnancy. A pregnant woman always should report any vaginal bleeding to her health care provider immediately. While all women with high blood pressure during pregnancy face some increased risk of abruption and the other complications discussed above, the risk is greatest in women who have preeclampsia along with chronic high blood pressure.3

Preeclampsia also can quickly progress to a rare but life-threatening condition called eclampsia, causing seizures and sometimes coma. Fortunately, eclampsia is rare in women who receive regular prenatal care. At each prenatal visit, blood pressure is measured and urine is checked for protein, so that preeclampsia can be diagnosed and treated before it can progress to eclampsia.

How is preeclampsia treated?
The only cure for preeclampsia is delivery. However, this is not always best for the baby. So treatment depends upon how severe the problem is and how far along a woman is in her pregnancy. If a woman is at term (37 to 40 weeks), the preeclampsia is mild, and her cervix has begun to thin and dilate (signs that it’s ready for delivery), her health care provider probably will recommend inducing labor. This prevents any potential complications that could develop if the pregnancy continues and the preeclampsia worsens. If her cervix is not yet ready for labor, her provider may recommend medication to help prepare her cervix for induction or continue to monitor her and her baby closely until labor starts on its own.

If a woman develops mild preeclampsia before her 37th week, her provider probably will recommend that she reduce her activities. In some cases, hospitalization may be recommended, though most women can be treated at home. Her baby’s well-being will be closely monitored with tests such as ultrasound and fetal heart rate monitoring. Blood tests probably will be recommended for the pregnant woman to see if the preeclampsia is progressing and harming her health.

If a woman has severe preeclampsia, she should be hospitalized. Her health care provider will probably recommend inducing labor if she is beyond 33 to 34 weeks gestation.4 At this stage of pregnancy, the risk of prematurity is generally outweighed by the risk of progression to eclampsia. Before inducing labor, doctors generally treat women who are at less than 34 weeks gestation with a drug called a corticosteroid that helps speed maturity of the fetal lungs to reduce the risk of prematurity-related problems. A woman who develops severe preeclampsia at less than 32 weeks gestation sometimes can be monitored closely in the hospital, to prolong the pregnancy safely while her baby matures.

Sometimes, a woman’s blood pressure continues to rise despite treatment with blood pressure medications, and her baby must be delivered early to prevent serious health problems in the mother, such as stroke, liver damage and seizures. Babies born early may have difficulties due to prematurity, such as trouble breathing. Most of these infants will do better in an intensive care nursery than if they had stayed in the uterus.

About 10 percent of women with severe preeclampsia also develop a disorder called HELLP (an acronym for Hemolysis, Elevated Liver enzymes, and Low Platelet count) syndrome, which is characterized by blood and liver abnormalities.5 Symptoms may include nausea and vomiting, headache, upper abdominal pain and general malaise. Women with HELLP syndrome, which also can develop in the first 48 hours after delivery, are treated with medications to control blood pressure and prevent seizures, and sometimes with blood transfusions. Women who develop HELLP syndrome during pregnancy almost always require early delivery to prevent serious complications.

What causes preeclampsia and who is at risk?
Doctors do not know what causes preeclampsia. However, women are more susceptible if they have any of these risk factors :

First pregnancy
Family history of preeclampsia
Personal history of chronic high blood pressure, kidney disease, diabetes, systemic lupus erythematosus (a disease often characterized in its early stages by arthritis-like stiffness, a butterfly-shaped rash across the nose and cheeks, fatigue and weight loss), and certain thrombophilias
Multiple pregnancy
Age less than 20 years, or over 35
African-American
Higher than normal weight
Personal history of preeclampsia

Can preeclampsia and gestational hypertension be prevented?
Currently, there is no way to prevent preeclampsia or gestational hypertension. However, a 1999 British study suggested that some high-risk women (including women who had preeclampsia in a previous pregnancy) may be able to reduce their risk of preeclampsia by taking vitamins C and E through the second half of pregnancy.6 The high-risk women who took the vitamins reduced their risk of developing preeclampsia by about 75 percent. The researchers caution that more studies are needed before this treatment can be widely recommended. Other treatments that looked promising in early studies (such as aspirin and calcium) have not proven helpful in preventing preeclampsia.

References
1. American College of Obstetricians and Gynecologists. Chronic Hypertension in Pregnancy. ACOG Practice Bulletin, number 29, July 2001.

2. American College of Obstetricians and Gynecologists. Diagnosis and Management of Preeclampsia and Eclampsia. ACOG Practice Bulletin, number 33, January 2002.

3. Roberts, J.M., et al. Summary of the NHLBI Working Group on Research on Hypertension During Pregnancy. Hypertension, volume 41, March 2003, pages 437-445.

4. Sibai, B.M. Diagnosis and Management of Gestational Hypertension and Preeclampsia. Obstetrics and Gynecology, volume 102, number 1, July 2003, pages 181-192.

5. Moldenhauer, J.S. and Sibai, B.M. Hypertensive Disorders of Pregnancy, in Scott, J.R. et al (eds): Danforth’s Obstetrics and Gynecology, Ninth Edition. Philadelphia, Lippincott Williams & Wilkins, 2003, pages 257-271.

6. Chappell, L.C., et al. Effect of Antioxidants on the Occurrence of Preeclampsia in Women at Increased Risk: A Randomized Trial. Lancet, volume 354, September 4, 1999, pages 810-816.

Blood Pressure Category	Systolic (mm Hg)		Diastolic (mm Hg)
Normal	less than 120	and	less than 80
Prehypertension	120–139	or	80–89

High
Stage 1	140–159	or	90–99
Stage 2	160 or higher	or	100 or higher

BLOOD PRESSURE & HIGH BLOOD PRESSURE

HYPERTENSION CLASSIFICATION

RISK FACTORS

SMOKING & HIGH BLOOD PRESSURE

HYPERTENSION DURING PREGNANCY