Secondary Hypertension
From WebMD.com

Causes of Secondary Hypertension
   In about 10% of people, high blood pressure is caused by another disease. If that is the case, it is called secondary hypertension. In such cases, when the root cause is treated, blood pressure usually returns to normal or is significantly lowered. These causes include the following conditions:

• Chronic kidney disease
• Sleep apnea
• Tumors or other diseases of the adrenal gland
• Coarctation of the aorta -- A narrowing of the aorta that you are born with that can cause high blood pressure in the arms
• Pregnancy
• Use of birth control pills
• Alcohol addiction
• Thyroid dysfunction

In the other 90% of cases, the cause of high blood pressure is not known (primary hypertension). Although the specific cause is unknown, certain factors are recognized as contributing to high blood pressure.

Factors That Can't Be Changed

• Age: The older you get, the greater the likelihood that you will develop high blood pressure, especially systolic, as your arteries get stiffer. This is largely due to arteriosclerosis, or "hardening of the arteries."
• Race: African-Americans have high blood pressure more often than whites. They develop high blood pressure at a younger age and develop more severe complications sooner.
• Family history (heredity): The tendency to have high blood pressure appears to run in families.
• Gender: Generally men have a greater likelihood of developing high blood pressure than women. This likelihood varies according to age and among various ethnic groups.

Factors That Can Be Changed

• Obesity: Obesity is defined as being 30% or more over your healthy body weight. It is very closely related to high blood pressure. Indeed, obese people are two to six times more likely to develop high blood pressure than people whose weight is within a healthy range. Medical professionals strongly recommend that all obese people with high blood pressure lose weight until they are within 15% of their healthy body weight. Your health care provider can help you calculate your healthy body weight range.
• Sodium (salt) sensitivity: Some people have high sensitivity to sodium (salt), and their blood pressure goes up if they use salt. Reducing sodium intake tends to lower their blood pressure. Americans consume 10-15 times more sodium than they need. Fast foods and processed foods contain particularly high amounts of sodium. Many over-the-counter medicines, such as painkillers, also contain large amounts of sodium. Read labels to find out how much sodium is contained in food items. Avoid those with high sodium levels. Your goal should be to consume no more than 1,500 mg of sodium per day.
• Alcohol use: Drinking more than 1-2 drinks of alcohol per day tends to raise blood pressure in those who are sensitive to alcohol.
• Birth control pills (oral contraceptive use): Some women who take birth control pills develop high blood pressure.
• Lack of exercise (physical inactivity): A sedentary lifestyle contributes to the development of obesity and high blood pressure.
• Drugs: Certain drugs, such as amphetamines (stimulants), diet pills, and some pills used for cold and allergy symptoms, tend to raise blood pressure.

Secondary Hypertension

From Mayo Clinic Staff
Some people have high blood pressure caused by an underlying condition. This type of high blood pressure, called secondary hypertension, tends to appear suddenly and cause higher blood pressure than does primary hypertension. Various conditions and medications can lead to secondary hypertension, including:

• Obstructive sleep apnea
• Kidney problems
• Adrenal gland tumors
• Thyroid problems
• Certain defects in blood vessels you're born with (congenital)
• Certain medications, such as birth control pills, cold remedies, decongestants, over-the-counter pain relievers and some prescription drugs
• Illegal drugs, such as cocaine and amphetamines
• Alcohol abuse or chronic alcohol use

Secondary hypertension (secondary high blood pressure) is high blood pressure that's caused by another medical condition. Secondary hypertension differs from the usual type of high blood pressure (essential hypertension), which is often referred to simply as high blood pressure. Essential hypertension, also known as primary hypertension, has no clear cause and is thought to be linked to genetics, poor diet, lack of exercise and obesity.

Secondary hypertension can be caused by conditions that affect your kidneys, arteries, heart or endocrine system. Secondary hypertension can also occur during pregnancy.

Proper treatment of secondary hypertension can often control both the underlying condition and the high blood pressure, which reduces the risk of serious complications — including heart disease, kidney failure and stroke.

Symptoms
By Mayo Clinic Staff

Like primary high blood pressure (hypertension), secondary hypertension usually has no specific signs or symptoms, even if your blood pressure has reached dangerously high levels.

Some people may experience headaches from secondary hypertension, but it's difficult to know if high blood pressure or something else is causing the headaches.

If you've been diagnosed with high blood pressure, having any of these signs may mean your condition is secondary hypertension:

• High blood pressure that doesn't respond to blood pressure medications (resistant hypertension)
• Very high blood pressure — systolic blood pressure over 160 millimeters of mercury (mm Hg) or diastolic blood pressure over 100 mm Hg
• A blood pressure medication or medications that previously controlled your blood pressure no longer work
• Sudden-onset high blood pressure before age 30 or after age 55
• No family history of high blood pressure
• No obesity

When to see a doctor
If you have a condition that can cause secondary hypertension, you may need your blood pressure checked more frequently. Ask your doctor how often to have your blood pressure checked.

Causes
By Mayo Clinic Staff

A number of conditions can cause secondary hypertension. These include:

• Diabetes complications (diabetic nephropathy). Diabetes can damage your kidneys' filtering system, which can lead to high blood pressure.
• Polycystic kidney disease. In this inherited condition, cysts in your kidneys prevent the kidneys from working normally and can raise blood pressure.
• Glomerular disease. Your kidneys filter waste and sodium using microscopic-sized filters called glomeruli that can sometimes become swollen. If the swollen glomeruli can't work normally, you may develop high blood pressure.

• Renovascular hypertension. This is a type of secondary hypertension caused by narrowing (stenosis) of one or both arteries leading to your kidneys. Renovascular hypertension can cause severe hypertension and irreversible kidney damage. It's often caused by the same type of fatty plaques that can damage your coronary arteries (atherosclerosis) or a separate condition in which the muscle and fibrous tissues of the renal artery wall thicken and harden into rings (fibromuscular dysplasia).
  
• Cushing syndrome. In this condition, corticosteroid medications themselves may cause secondary hypertension, or hypertension may be caused by a pituitary tumor or other factors that cause the adrenal glands to produce too much of the hormone cortisol. This raises blood pressure.
• Aldosteronism. In this condition, a tumor in the adrenal gland, increased growth of normal cells in the adrenal gland or other factors cause the adrenal glands to release an excessive amount of the hormone aldosterone. This makes your kidneys retain salt and water and lose too much potassium, which raises blood pressure.
• Pheochromocytoma. This rare tumor, usually found in an adrenal gland, increases production of the hormones adrenaline and noradrenaline, which can lead to long-term high blood pressure or short-term spikes in blood pressure.
• Thyroid problems. When the thyroid gland doesn't produce enough thyroid hormone (hypothyroidism) or produces too much thyroid hormone (hyperthyroidism), high blood pressure can result.
• Hyperparathyroidism. The parathyroid glands regulate levels of calcium and phosphorus in your body. If the glands secrete too much parathyroid hormone, the amount of calcium in your blood rises — which triggers a rise in blood pressure.
• Coarctation of the aorta. With this defect you're born with, the body's main artery (aorta) is narrowed (coarctation). This forces the heart to pump harder to get blood through the aorta and to the rest of your body. This, in turn, raises blood pressure — particularly in your arms.
• Sleep apnea. In this condition, often marked by severe snoring, breathing repeatedly stops and starts during sleep, causing you to not get enough oxygen. Not getting enough oxygen may damage the lining of the blood vessel walls, which may make your blood vessels less effective in regulating your blood pressure. In addition, sleep apnea causes part of the nervous system to be overactive and release certain chemicals that increase blood pressure.
• Obesity. As you gain weight, the amount of blood circulating through your body increases. This puts added pressure on your artery walls, increasing your blood pressure. Excess weight often is associated with an increase in heart rate and a reduction in the capacity of your blood vessels to transport blood. In addition, fat deposits can release chemicals that raise blood pressure. All of these factors can cause hypertension.
• Pregnancy. Pregnancy can make existing high blood pressure worse, or may cause high blood pressure to develop (pregnancy-induced hypertension or preeclampsia).
• Medications and supplements. Various prescription medications — such as pain relievers, antidepressants and drugs used after organ transplants — can cause or aggravate high blood pressure in some people. Birth control pills, decongestants and certain herbal supplements, including ginseng, licorice and ephedra (ma huang), may have the same effect. Many illegal drugs, such as cocaine and methamphetamine, also increase blood pressure.

Risk factors
By Mayo Clinic Staff

The greatest risk factor for having secondary hypertension is having a medical condition that can cause high blood pressure, such as kidney, artery, heart or endocrine system problems.

Complications
By Mayo Clinic Staff

Secondary hypertension can worsen the underlying medical condition you have that's causing your high blood pressure. If you don't receive treatment, secondary hypertension can also be associated with other medical conditions, such as:

:Damage to your arteries. This can result in hardening and thickening of the arteries (atherosclerosis), which can lead to a heart attack, stroke or other complications.

• Aneurysm. Increased blood pressure can cause your blood vessels to weaken and bulge, forming an aneurysm. If an aneurysm ruptures, it can be life-threatening.
• Heart failure. To pump blood against the higher pressure in your vessels, your heart muscle thickens. Eventually, the thickened muscle may have a hard time pumping enough blood to meet your body's needs, which can lead to heart failure.
• Weakened and narrowed blood vessels in your kidneys.This can prevent these organs from functioning normally.
• Thickened, narrowed or torn blood vessels in the eyes.This can result in vision loss.
• Metabolic syndrome. This syndrome is a cluster of disorders of your body's metabolism — including increased waist circumference, high triglycerides, low high-density lipoprotein (HDL) cholesterol (the "good," cholesterol), high blood pressure, and high insulin levels. If you have high blood pressure, you're more likely to have other components of metabolic syndrome. The more components you have, the greater your risk of developing diabetes, heart disease or stroke.
• Trouble with memory or understanding. Uncontrolled high blood pressure also may affect your ability to think, remember and learn. Trouble with memory or understanding concepts is more common in people who have high blood pressure.

Tests and diagnosis
By Mayo Clinic Staff

To diagnose secondary hypertension, your doctor will first take a blood pressure reading using an inflatable cuff, just as your blood pressure is measured during a typical doctor's appointment. Your doctor may not diagnose you with secondary hypertension based on one higher than normal blood pressure reading — it may take three to six high blood pressure measurements at separate appointments to diagnose secondary hypertension.

Your doctor will also want to check other markers to pinpoint the cause of your high blood pressure. These could include:

• A blood test. Your doctor may want to check your potassium, sodium, total cholesterol and triglycerides, and other chemicals in your blood to help make a diagnosis.
• Urinalysis. Your doctor may want to check your urine for markers that could show your high blood pressure is caused by another medical condition.
• Ultrasound of your kidneys. Since many kidney conditions are linked to secondary hypertension, your doctor may order an ultrasound of your kidneys and blood vessels. In this noninvasive test, a technician will run an instrument called a transducer over your skin. The transducer, which produces sound waves, measures how the sound waves bounce off your kidneys and sends images created by the sound waves to a computer monitor.
• Electrocardiogram (ECG). If your doctor thinks your secondary hypertension may be caused by a heart problem, he or she may order an electrocardiogram. In this noninvasive test, sensors (electrodes) that can detect the electrical activity of your heart are attached to your chest and sometimes to your limbs. An ECG measures the timing and duration of each electrical phase in your heartbeat.

Treatments and drugs
By Mayo Clinic Staff

Often, an underlying medical condition requires treatment with medications or surgery. Once an underlying condition is effectively treated, secondary hypertension may decrease or even return to normal. Often, however, lifestyle changes — such as eating healthy foods, increasing physical activity and maintaining a healthy weight — can help keep your blood pressure low.

You may need to continue to take blood pressure medication as well, and any underlying medical condition you have may affect your doctor's choice of medication. ossible drug choices include:

• Thiazide diuretics. Diuretics, sometimes called water pills, are medications that act on your kidneys to help your body eliminate sodium and water, reducing blood volume. Thiazide diuretics are often the first — but not the only — choice in high blood pressure medications. These medications are often generic and tend to be less expensive than other high blood pressure medications. If you're not taking a diuretic and your blood pressure remains high, talk to your doctor about adding one or replacing a drug you currently take with a diuretic. Possible side effects include an increased need to urinate and a higher risk of sexual dysfunction.
• Beta blockers. These medications reduce the workload on your heart and open your blood vessels, causing your heart to beat slower and with less force. When prescribed alone, beta blockers don't work as well in blacks — but they're effective when combined with a thiazide diuretic. Possible side effects include fatigue, sleep problems, a slowed heart rate, and coldness in your hands and feet. In addition, beta blockers generally aren't prescribed for people with asthma, as they can increase muscle spasms in the lungs.
• Angiotensin-converting enzyme (ACE) inhibitors. These medications help relax blood vessels by blocking the formation of a natural chemical that narrows blood vessels. ACE inhibitors may be especially important in treating high blood pressure in people with coronary artery disease, heart failure or kidney failure. Like beta blockers, ACE inhibitors don't work as well in blacks when prescribed alone, but they're effective when combined with a thiazide diuretic. Possible side effects include dizziness and cough, and these medications aren't recommended during pregnancy.
• Angiotensin II receptor blockers. These medications help relax blood vessels by blocking the action — not the formation — of a natural chemical that narrows blood vessels. Like ACE inhibitors, angiotensin II receptor blockers often are useful for people with coronary artery disease, heart failure or kidney failure. These medications have fewer potential side effects than do ACE inhibitors, but are also not used during pregnancy.
• Calcium channel blockers. These medications help relax the muscles of your blood vessels. Some slow your heart rate. Calcium channel blockers may work better for blacks than do ACE inhibitors or beta blockers alone. Possible side effects include water retention, dizziness and constipation. And, a word of caution for grapefruit lovers. Grapefruit juice interacts with some calcium channel blockers, increasing blood levels of the medication and putting you at higher risk of side effects. Ask your doctor or pharmacist if your medication is affected by grapefruit juice.
• Direct renin inhibitors. Recent treatment for hypertension includes direct renin inhibitors, such as aliskiren. Aliskiren relaxes and widens the arteries by preventing the action of renin. Renin is the initial enzyme in a cascade of steps in the production of chemicals (angiotensin, aldosterone, others) important in cardiovascular health and disease. The Food and Drug Administration strongly cautions against using aliskiren in combination with ACE inhibitors or angiotensin II receptor blockers in people with diabetes or moderate to severe kidney problems. Common side effects of aliskiren include dizziness and diarrhea.

Treatment can sometimes be complicated. You may need more than one medication combined with lifestyle changes to control your high blood pressure. And your doctor will want to see you more frequently until your blood pressure is stabilized, possibly as frequently as once a month.

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