General Medicine

Lecture 1 Dr. Amera Alkaisi

HypertensionDefinition

Abnormally high arterial blood pressure that is usually indicated by an adult systolic blood pressure of 140 mm Hg or greater or a diastolic blood pressure of 90 mm Hg or greater

Systolic pressure: Blood pressure when the heart beats 

Diastolic pressure: Blood pressure when the heart is at rest  

Blood pressure 

Is the force of blood pushing against the walls of arteries as it flows through them. When the muscular walls of arteries relaxed or dilated, the pressure of the blood flowing through them is lower than when the artery walls narrow, or constrict

Types

1- Primary (essential) hypertension2- Secondary hypertension

Etiology

1. Primary (essential) hypertension

For most adults, there's no identifiable cause of high blood pressure. This type of high blood pressure, called essential hypertension or primary hypertension, tends to develop gradually over many years.

2. Secondary hypertension

Some people have high blood pressure caused by an underlying condition. This type of high blood pressure tends to appear suddenly and cause higher blood pressure than does primary hypertension.

Conditions and medications can lead to secondary hypertension, including:

Kidney problems:  If the kidneys cannot rid the body of excess salt and water, blood pressure goes up. Kidney infections, a narrowing of thearteries that carry blood to the kidneys, called renal artery stenosis, and other kidney disorders can disturbthe salt and water balance

Adrenalgland tumors: Cushing's syndrome and tumors of the pituitary and adrenal glands often increase levels of the adrenal glandhormones cortisol, adrenalin, and aldosterone, which can cause hypertension

Thyroid problems Certain defects in blood vessels you're born with (congenital)

Certain medication such as oral contraceptives pills

decongestants Pain relievers and some prescription drugs(NAID) Illegal drugs, such as cocaine and amphetamines Alcohol abuse or chronic alcohol use Obstructive sleep apnea

Typically results in a thickening and inelasticity of arterial walls and hypertrophy of the left heart ventricle

Risk factors

Age The risk of high blood pressure increases with age. Through early middle age, or about age 45,

SexHigh blood pressure is more common in men. Women are more likely to develop high blood pressure after age 65.

Race High blood pressure is particularly common among blacks, often developing at an earlier age than it does in whites. Serious complications, such as stroke, heart attack, and kidney failure, also are more common in blacks.

Heredity or Family history. High blood pressure tends to run in families. Obesity

As the weigh increases the more blood is need to supply oxygen and nutrients to the tissues. As the volume of blood circulated through the blood vessels increases, the more pressure exerted on the arterial walls

Inactive lifestyle

People who are inactive tend to have higher heart rates. The higher the heart rate, the harder the heart must work with each contraction and the stronger the force on arteries. Lack of physical activity also increases the risk of being overweight.

Using tobacco. Smoking or chewing tobacco immediately blood pressure temporarily and the chemicals in tobacco can damage the lining of arterial walls lead to narrowing of the arteries, increasing blood pressure.

Salt sensitivity or too much salt (sodium) in your diet. Too much sodium in diet can cause body to retain fluid, which increases blood pressure.

Too little potassium in the diet. Potassium helps balance the amount of sodium in the cells. If you don't get enough potassium in your diet or

retain enough potassium, you may accumulate too much sodium in your blood.

Too little vitamin D in the diet. It's uncertain if having too little vitamin D in your diet can lead to high blood pressure. Vitamin D may affect an enzyme produced by kidneys that affects blood pressure.

Heavy alcohol consumption

Over time, heavy drinking can damage their heart. Having more than two drinks a day for men and more than one drink a day for women may affect your blood pressure.If you drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women of all ages and men older than age 65, and up to two drinks a day for men age 65 and younger.

Stress. High levels of stress can lead to a temporary increase in blood pressure.

Certain chronic conditions. Certain chronic conditions also may increase your risk of high blood pressure, such as kidney disease and sleep apnea.

Sometimes pregnancy contributes to high blood pressure, as well.

Hypertension in children

Although high blood pressure is most common in adults, children may be at risk, too. For some children, high blood pressure is caused by:

Problems with the kidneys or heart. For a growing number of kids, poor lifestyle habits, such as an unhealthy

diet, obesity and lack of exercise, contribute to high blood pressure. A 2003 report foundthat the rise in incidence of high blood pressure amongchildren is most likely due to an increase in the numberof overweight and obese children and adolescents.

Causes

1- Increase in cardiac output2- Peripheral resistance caused by abnormally reduced arteriolar radius

Renal hypertension

Increased release of rennin from the kidney which increases the generation of potent vasoconstrictor angiotensin II

Signs & Symptoms

Most people with high blood pressure have no signs or symptoms, even if blood pressure readings reach dangerously high levels.

Few people with early-stage high blood pressure may have Occipital headaches Dizziness and weakness Tingling of the hands and feets Vision changes Palpitations Fainting Shortness of breath Chest pain Ringing ears

Nausea

Problems with vision Irregular heartbeat Blood in the urine a few more nosebleeds than normal, these signs and symptoms usually

don't occur until high blood pressure has reached a severe or life-threatening stage

Diagnosis

Medical history Family history Physical examination and investigations to evaluate hypertension includes:

Several blood pressurereadings at different times and in different positions The pulse, reflexes Height and weight are checked andrecorded.  Internal organs are palpated, or felt, todetermine if they are enlarged.

Ophthalmoscopy: Examination of the blood vessels in the eye; Because hypertension can cause damage to the bloodvessels in the eyes.To check any thickening, narrowing, or hemorrhages in the blood vessels.

Chest x ray A chest x ray can detect an enlarged heart, othervascular (heart) abnormalities, or lung disease.

Electrocardiograph (ECG) An electrocardiogram (ECG) measures the electrical activity of the heart.  It can detect if the heart muscle isenlarged and if there is damage to the heart muscle from blocked arteries.

Blood and urine tests.Urine and blood tests may be done to evaluate health and to detect the presence of disorders that might cause hypertension.

When you must check your blood pressure

Blood pressure reading should be taken at least every two years starting at age 18.

Blood pressure should be checked in both arms to determine if there is a difference

Measuring blood pressure 

Blood pressure is measured in millimeters of mercury (mm Hg) For example, if a person's systolicpressure is 120 and diastolic pressure is 80, it is written as 120/80 mm Hg. 

The American Heart Association haslong considred blood pressure less than 140 over 90normal for adults

However, the National Heart, Lung, andBlood Institute in Bethesda, Maryland released newclinical guidelines for blood pressure in 2003, lowering thestandard normal readings. A normal reading was loweredto less than 120 over less than 80.

Diagnosis of hypertension 

Because hypertension doesn't cause symptoms, it isimportant to have blood pressure checked regularly. Diagnosis made only when a person has multiple high blood pressure readings over a period of time.Diagnosis of hypertension usually is made basedon two or more readings after the first visit.

Measurement blood pressure 

Blood pressure is measured with a sphygmomanometer

A cloth covered rubber cuff is wrapped around the upper arm and inflated. When thecuff is inflated, an artery in the arm is squeezed to momentarily stop the flow of blood. Then, the air is let out of the cuff while a stethoscope placed over the artery is used to detect the sound of the blood spurting backthrough the artery. This first sound is the systolic pressure,  the pressure when the heart beats. The last sound heard as the rest of the air is released is the diastolic pressure, the pressure between heart beats. Both sounds are recorded on the mercury gauge on the sphygmomanometer.

Normal adult blood pressure is defined as a blood pressure of 120 mm Hg1 when the heart beats (systolic) and a blood pressure of 80 mm Hg when the heart relaxes (diastolic)

Blood pressure measurements are classified in stages,according to severity:

Normal blood pressure: less than less than 120/80mm Hg Pre-hypertension: 120-129/80-89 mm Hg Stage 1 hypertension: 140-159/90-99 mm Hg Stage 2 hypertension: at or greater than 160-179/100-109 mm Hg

Treatment

Primary hypertension:There is no cure, but blood pressure can almost always be lowered with the correct treatment

Secondary hypertension Successful treatment of the underlying disorder may cure the secondary hypertension

Treatment to lower blood pressure may include:

Changes in diet(eating more fruit and vegetables) Getting regular exercise Taking antihypertensive medication

Lifestyle changes that may reduce blood pressure byabout 5 to 10 mm Hg include:

Reducing salt intake: less than 5 g of salt per day (just under a teaspoon) Reducing fat intake Losing weight: every 5 kg of excess weight lost can reduce systolic blood

pressure by 2 to 10 points Getting regular exercise: (at least 30 minutes a day) Quitting smoking Reducing alcohol consumption Managing stress

The choice of medication depend on:

The stage of hypertension Side effects  Other medical conditions the patient may have,and other medicines th

e patient is taking. If treatment with a single medicine fails to lower blood

pressure enough, a different medicine may be tried oranother medicine may be added to the first.

 Patients withmore severe hypertension may initially be given acombination of medicines to control their hypertension.Combining antihypertensive medicines with differenttypes of action often controls blood pressure with smallerdoses of each drug than would be needed for just one.

Antihypertensive medicines fall into several classes of drugs:

Diuretics Diuretics help the kidneys eliminate excess salt andwater from the body's tis

sues and the blood. This helpsreduce the swelling caused by fluid buildup in the tissues.The reduction of fluid dilates the walls of arteries andlowers blood pressure. New guidelines released in 2003suggest diuretics as the first drug of choice for mostpatients with high blood pressure and as part of anymulti-drug combination.

Beta-blockers

Betablockers lower blood pressure by acting on the nervous system to slow the heart rate and reduce the force of the heart's contraction. They are used with caution in patients with heart failure, asthma, diabetes, or circulation problems in the hands and feet.

Calcium channel blockers

Calcium channel blockers block the entry of calcium intomuscle cells in artery walls. Muscle cells need calcium toconstrict, so reducing their calcium keeps them more relaxed and lowers blood pressure.

Angiotensin converting enzyme inhibitors (ACE inhibitors)

ACE inhibitors block the production of substances thatconstrict blood vessels. They also help reduce the buildup of water and salt in the tissues. They often are givento patients with heart failure, kidneydisease, ordiabetes. ACE in hibitors may be used together withdiuretics.

Alpha-blockers

Alphablockers act on the nervous system to dilatearteries and reduce the force of the heart's contractions.

Alpha-beta blockers

Alpha-beta blockers combine the actions of alpha and beta blockers.

Vasodilators

Vasodilators act directly on arteries to relax their walls soblood can move more easily through them. They lowerblood pressure rapidly and are injected in hypertensiveemergencies when patients have dangerously high bloodpressure.

peripheral acting adrenergic antagonist

Act on the nervous system to relax arteries and reduce the force of the heart's contractions. They usually are prescribed together with a diuretic. 

Centrally acting agonists

Also act on the nervous systemto relax arteries and slow the heart rate. They are usuallyused with other antihypertensive medicines

Untreated, hypertension can lead to the following medical conditions:

Atherosclerosis Heart attack Stroke Enlarged heart Kidney damage