HYPERTENSION AN OVERVIEW Cmpiled by Campbell M Gld (2008) CMG Archives http://campbellmgld.cm IMPORTANT The health infrmatin cntained herein is nt meant as a substitute fr advice frm yur physician, r ther health prfessinal. The fllwing material is intended fr general interest nly; and it shuld nt be used t diagnse, treat, r cure any cnditin whatever. If yu are cncerned abut any health issue, symptm, r ther indicatin, yu shuld cnsult yur regular physician, r ther health prfessinal. Cnsequently, the Authr cannt accept respnsibility fr any individual wh misuses the infrmatin cntained in this material. Thus, the reader is slely respnsible fr all f the health infrmatin cntained herein. Hwever, every effrt is made t ensure that the infrmatin in this material is accurate; but, the Authr is nt liable fr any errrs in cntent r presentatin, which may appear herein. Cntents Intrductin... 2 Knwn Causes... 2 Factrs Related T Hypertensin... 2 Disease Prcess... 3 Cmplicatins... 3 Treatment... 4 Hw t Take a Bld Pressure Reading... 4 Interpretatin... 5 Bld Pressure in Adults 18 Yrs and Older... 5 Bld Pressure in Children and adlescents... 5 Autmatic Measuring Devices... 6 Appendix - Hyptensin... 7 Hyptensin (Lw Bld Pressure)... 7 Factrs Related T Hyptensin (Lw Bld Pressure)... 7 1
Intrductin Hypertensin, r high bld pressure, is a cmmn disrder, ften withut symptms and marked by high bld pressure persistently exceeding 140/90mm Hg. There are three main types f hypertensin, namely, 1) Essential Hypertensin, 2) Secndary Hypertensin, and 3) Malignant Hypertensin. 1) Essential Hypertensin, als called primary hypertensin, is the mst frequent kind, and it has n ne knwn cause and is ften the nly manifested disrder. Hwever, the risk f hypertensin is increased by verweight, a high sdium level in the bld, a high chlesterl level, and a family histry f high hypertensin, strke, and/r heart disease. High bld pressure is always a health risk, especially fr develping heart disease. 2) Secndary Hypertensin is high bld pressure linked t diseases f the kidneys, lungs, glands, and vessels. 3) Malignant Hypertensin, als called accelerated hypertensin, is marked by a diastlic pressure higher than 120, severe headaches, blurred visin and cnfusin, and may result in a heart attack r strke. Malignant hypertensin is the mst life-threatening frm f hypertensin, and is marked by very high bld pressure that may damage the tissues f small vessels, the brain, the eyes (especially the retinas), heart, and kidneys. Malignant hypertensin may be caused by a variety f factrs, such as stress, a family histry f the disease, being verweight, tbacc, birth cntrl and ther hrmne based pills, high intake f table salt (sdium chlride), an inactive life-style, and general aging. Many patients with this cnditin als have signs f lw bld ptassium, bld that is alkaline, and the release f high levels f an adrenal gland hrmne (aldsterne). Knwn Causes Knwn causes f hypertensin include adrenal prblems, ver-active thyrid gland, certain pregnancies, and kidney disrders. Hypertensin is mre cmmn in men than in wmen, and is twice as great in blacks as in whites. Persns with mild r mderate hypertensin may have n symptms, r they may experience headaches, especially n rising, ringing in the ears, lightheadness, easy fatigability, and the feeling that their heart is beating wildly. With sustained hypertensin, artery walls becme thickened and resistant t bld flw, and, as a result, the bld supply t the heart may be reduced, thus causing angina r heart attack. High bld pressure is ften accmpanied by anxiety attacks, rapid r irregular heart beat, prfuse sweating, pallr, nausea, and, in sme cases, fluid in the lungs. Drugs used t treat hypertensin include diuretics (e.g. thiazide derivatives); vasdilatrs (e.g. hydralazine and prazsin); sympathetic nervus system (SNS) depressants (e.g. rauwlfia alkalids); sympathetic nervus system (SNS) inhibitrs (e.g. guanethidine and methyldpa); and ganglinic blcking agents (e.g. clnidine and prpranll). Patients with high bld pressure are advised t fllw a lw-sdium, lw-saturated-fat diet, t reduce calries, t cntrl besity, t exercise, t avid stress, and t take adequate rest. Factrs Related T Hypertensin There are at least ten majr risk factrs related t hypertensin (high bld pressure): Age. Studies have shwn a tendency fr bld pressure t increase with age. In a study amng peple 55 years and lder, at least 59% had hypertensin. Genetic influence. A substantial number f peple are brn with a tendency twards hypertensin. If ne f yur parents has high bld pressure yu are twice as likely t have hypertensin as smene whse parents have nrmal bld pressure. 2
Ethnic backgrund. Fr instance, in the USA, hypertensin is much mre prevalent amng Negres than amng Caucasians. Gender. Typically, during the first part f their lives, men have higher bld pressure measurements that t wmen. Then, as wmen mve int their sixties, they catch up t and then exceed the measurements f the men. Usually, wmen suffer fewer cmplicatins frm the same levels f hypertensin than d men. Salt (sdium) Sensitivity. Abut half f thse with hypertensin are salt-sensitive. That is, their bld pressure rises when they cnsume excessive amunts f salt (sdium), and drps when they reduce their salt (sdium) intake. Obesity. Imprtant scientific investigatins have linked hypertensin with besity. In the 'Framingham Heart Study', patients wh were 20% r mre ver their ideal weight were eight times mre likely t becme hypertensive. Excess upper-bdy fat has been assciated with ther threats t health, including: Diabetes. Hypertriglyceridemia (excessive levels f triglycerides, a fatty substance in the bld). Lw levels f HDL ('gd') chlesterl, which is assciated with prtectin against athersclersis (the build-up f fatty depsits in the bld vessels). Crnary heart disease. Alchl Abuse. Drinking any amunt f alchl, n matter small, has the ptential t elevate bld pressure. Hwever, research has indicated that sme individuals are mre alchlsensitive than thers. Stress. Research has indicated that there is a definite cnnectin between stress and hypertensin. S, stress is nw regarded as a definite risk factr fr hypertensin. A Sedentary lifestyle. Research cncludes that the mre physically fit yu are, the less likely yu are t suffer frm hypertensin. Cnversely, the mre sedentary yu are, the greater is yur risk f develping hypertensin. Nutritin and element intake. This includes high creatinine levels (a substance prduced when muscle tissue is brken dwn by the bdy, transprted by the bld, and excreted in the urine), caffeine, smking, fats, lw dietary fibre, lw ptassium, and lw calcium. Disease Prcess Hypertensin is a disease f the vascular regulatry system, in which the mechanisms that usually cntrl arterial pressure within a certain (nrmal) range are altered/malfunctining. The central nervus system and renal pressr system, as well as extracellular vlume, are the predminant mechanisms that cntrl arterial pressure. Thus, sme cmbinatin f factrs effects changes in ne r mre f these systems, ultimately leading t increased cardiac utput and increased peripheral resistance. This elevates the arterial pressure, reducing cerebral perfusin and the cerebral xygen supply, increasing the mycardial wrklad and xygen cnsumptin, and decreasing the bld flw t/and xygenatin f the kidneys. Ptential Cmplicatins Cmplicatins f hypertensin include athersclertic disease, left ventricular failure, cerebrvascular insufficiency with r withut strke, retinal hemrrhage, and renal failure. When the pathlgic 3
prcess is accelerated, malignant hypertensin results, the bld pressure becmes extremely high, and nephrsclersis, encephalpathy, and cardiac failure rapidly ensue. Treatment Treatment f underlying disease in secndary hypertensin Systematic exercise Restrictin f dietary sdium Decreased alchl intake Quitting smking, stress reductin Weight lss, if indicated Regular mnitring f bld pressure Adpting an apprpriate dietary regime Taking apprpriate medicatins/supplements Mnitring fr ptential lng-term cmplicatins Hw t Take a Bld Pressure Measurement Using a Traditinal Measuring Device Bld pressure readings can be self-taken r taken by anther persn, and are measured as fllws: T measure bld pressure there will be a measuring device (Sphygmmanmeter - mercury based r anerid type (picture right - anerid type measuring device)) and a stethscpe (sme measuring devices have the stethscpe 'built-in'). Bld pressure is measured in terms f millimetres f mercury (mm Hg). The reading is made by either bserving a clumn f mercury r a dial n the measuring device. The cuff, cntaining the bladder, f the measuring device is carefully wrapped arund the upper arm. The cuff shuld be placed with the bladder part cvering as much f the inside f the upper arm as pssible. The stethscpe (picture right) is placed (if nt built in) n the inside f the upper arm, just abve the elbw jint. The measuring device is pumped, and the cuff bladder inflates (picture belw) and restricts the bld vessels in the upper arm. The measuring device is pumped until the pulse beat detected by the stethscpe disappears (e.g. <= 160mm Hg). The measuring device is slwly deflated, releasing the air ut f the cuff bladder, at a rate f 2 t 3mm Hg per secnd (r heartbeat). When the deflatin reaches a certain pint the bld begins t rush back int the clsed ff bld vessels. This flw will cause a beat r thumping sund t be detected thrugh the stethscpe. This is knwn as 'Krtkff Phase 1'. This sund signals the pint at which the bdy's bld pressure 4
vercmes the cuff resistance. This is the marker fr the SYSTOLIC bld pressure reading. The reading (e.g. 130mm Hg) is taken by bserving the mercury level r the dial n the measuring device. The deflatin prcess cntinues, and the beat cntinues t be detected thrugh the stethscpe. Precisely at the pint when the beat stps, knwn as 'Krtkff Phase 5', again the mercury level r dial reading is nted. This reading (e.g. 80mm Hg) represents the DIASTOLIC bld pressure. The tw-figures 130mm Hg and 80mm Hg are cmbined int the final result, 130/80mm Hg. This is then read as, 'ne-thirty-ver-eighty'. The measuring device-cuff is allwed t deflate cmpletely, and is remved frm the upper arm. Interpretatin The fllwing tables can be used t interpret the measurements: CLASSIFICATION OF BLOOD PRESSURE IN ADULTS 18 YEARS AND OLDER Bld Pressure Range Mm Hg Categry Fllw up by Dctr (Millimetres f Mercury) Systlic Bld Pressure, when Diastlic is less than 90 mm Hg Less than 140 mm Hg Nrmal Recheck within 2 years Brderline Islated Systlic If Systlic is in 140-199 mm 140-159 mm Hg Hypertensin Hg range, cnfirm within 2 mnths. Greater than 160 mm Hg Islated Systlic Hypertensin If Systlic is at r abve 200 mm Hg, evaluate r refer prmptly t surce f care within 2 weeks. Diastlic Bld Pressure Less than 85 mm Hg Nrmal Recheck within 2 years 85-89 mm Hg High Nrmal Recheck within 1 year 90-104 mm Hg Mild Hypertensin Cnfirm within 2 mnths 105-114 mm Hg Mderate Hypertensin Evaluate r refer prmptly t surce f care within 2 weeks Greater than 115 mm Hg Severe Hypertensin Evaluate r refer immediately t surce f care CLASSIFICATION OF BLOOD PRESSURE IN CHILDREN AND ADOLESCENTS Nte: The fllwing levels f bld pressure have been prpsed as the upper limits f nrmal. Age in Years Bld Pressure in Millimetres f Mercury (mm Hg) 15-18 years 135/90 mm Hg 11-14 years 125/85 mm Hg 6-10 years 120/80 mm Hg Belw 6 years 110/75 mm Hg 5
Autmatic Measuring Devices Tday, there are diverse bld pressure measuring devices. Fr autmatic devices, carefully fllw the perating instructins fr psture, bladder placement, and activatin, etc. When activated, the device autmatically inflates the cuff, takes the relevant measurements, and displays the results (Systlic Pressure, Diastlic Pressure, and Heart Rate) n a small screen. The cuff is then cmpletely deflated and the device is again ready fr use. With an autmatic device, the cuff is typically fitted arund the wrist (picture right) r the upper arm. 6
Appendix Hyptensin Hyptensin (Lw Bld Pressure) By mst current standards, the average nrmal bld pressure reading fr adults is 120/80 mm Hg. The Natinal Institutes f Health cnsider readings dwn t 110/70 mm Hg safe fr mst individuals. In general, if an individual is nt n antihypertensive medicatin and has measurements f 100/70 r belw, they have entered the realm f hyptensin (lw bld pressure). Factrs Related T Hyptensin (Lw Bld Pressure) There are three majr factrs related t hyptensin (lw bld pressure): End 1) Over-medicatin. 2) Nn-drug-related pstural hyptensin. This ccurs n standing. 3) Other cardivascular r rganic prblems (e.g. haemrrhage in the stmach, heart attack, prblem with bld flw t the lungs, tumur, etc). http://campbellmgld.cm 13112008/1 7