High Blood Pressure/Hypertension

High Blood Pressure is an extremely common problem which I see several times every day in my clinical practice.  The prevalence of high blood pressure (also called hypertension) goes up with age and weight.  However, I have some very young patients in my practice with hypertension also. 

Why do we worry about high blood pressure?  High blood pressure is associated with a significant increase in the risk of heart attack, stroke, congestive heart failure, kidney disease, and eye retinal damage.  

A recent, large, landmark study called the "SPRINT" study showed that keeping blood pressure close to 120/80 reduces heart attack, heart failure, and stroke risk by almost one-third, and overall risk of death by about 25%.  

Hypertension is generally defined as having elevated blood pressures (over 140 mm of mercury systolic or top number, or over 90 mm of mercury on the diastolic, or lower number, if you are under age 70), on more than one occasion, at least one to two weeks apart, with no other variables present that could cause high pressures.  That is, the patient is not in pain, not severely stressed, not on medication that might elevate blood pressure, not significantly ill.  

It is highly likely that with the results of this new SPRINT study, new guidelines for more intensive management of blood pressure will be coming out, probably with goals set depending on other current heart disease risk factors.  That is, if you have other risks for heart disease or stroke, such as smoking, obesity, diabetes, hight cholesterol, or a strong family history of early heart disease in your first-degree relatives, your "target blood pressure" may be lower than someone who does not have these risk factors. 

Diagnosis of High Blood Pressure:


We check blood pressures with every office visit of every patient (unless small kids).  This is because high blood pressure can show up at any time and typically has virtually NO symptoms.  SOME patients may occasionally feel some symptoms if their pressures are up--typically a sense of a mild/persistent headache, or pressure around their neck, or pulse-pounding, or mild lightheadedness.  If there are symptoms, they are usually very vague. 

Blood pressure should normally range from around 110 to 130 on the systolic side, and from 60 to 85 on the diastolic side.  It can vary widely over the course of a typical day and under different circumstances. 

The SYSTOLIC blood pressure is the pressure of the blood in the arteries (blood vessels leaving the heart) when the heart is in the active pumping phase--the heart is squeezing/forcing blood into the arteries.  Therefore this number reflects the pressures created by not only the heart squeezing blood, but the ability of the arteries to accommodate that increased volume of blood coming into the system.  Arteries should be rather expansile--flexible, able to open up.  In doing so they reduce the pounding effect of the pulse pressure down the blood vessel pipeworks system. 

The DIASTOLIC blood pressure is the pressure in the arterial system between heart beats.  The heart is relaxed, and is not pushing blood into the system.  The diastolic blood pressure reflects the general resistance of the arteries and arterioles (really small arteries).  Arteries and arterioles are wrapped with muscles that can constrict them.  These muscles are under the control of the autonomic nervous system.  They respond to numerous inputs--neurologic and hormonal--resulting in either relaxing the muscle, which widens the artery's opening, or tightening, which narrows the artery's opening. 

If the arteries and arterioles are relatively relaxed and "open," then the pressure of the blood within will be lower.  If the arteries are under some degree of squeeze effect, then the pressure will rise. 

I use the rather simple analogy of a powerful water pump (the heart) pumping water out of a pond, into a big firehose, that is then attached to several garden hoses (arteries) watering, say 15 separate lawns.  If those 15 garden hoses are clamped in a vise so that only a trickle is coming through, the pressure in the firehose will climb precipitously.  If we unclamp those 15 garden hoses completely, then the pressure in the firehose coming out of the pump diminishes. 

The important point of the analogy is, what happens to the water pump if those 15 clamps are kept clamped down for a long time?  The water pump starts to get overloaded.  In real life, most water pumps have a "pressure relief valve" that will dump water out of the pump if the pressure goes up too high.  The heart has no such pressure relief valve.  It just has to deal with the elevated pressures.  However, over time (years), the heart expands, the valves can leak, the the heart muscle changes and eventually heart failure can occur.  Heart failure does not mean the heart stops beating, it just means it can't handle the load and blood starts to back up on the incoming side of the heart pump. 

We measure blood pressure with a sphygmomanometer (SFIG-mo-muh-NOM-meter).  In 1726, Stephen Hales began measuring the height of the fountain of arterial blood shooting out of a punctured large artery of horses (we'll pretend that those horses' arteries were repaired and that they lived long and happy lives after that).  Now, we can buy very accurate battery-operated, electronic home blood pressure machines for around $50-$100. 

Here is a typical clinical scenario:  I'm seeing John Doe (not his real name) for a general physical.  He is 44 years old, a little overweight, and does some occasional exercise.  When my medical office assistant checks his blood pressure, it is 148/94.  So I go in and we talk and deal with his issues, and after a good 15 minutes or so I'll check it again.  It is now 144/92.  So it is NOT normal.  Does he have high blood pressure?  No, not really--since we don't have a series of elevated blood pressure measurements, I can't really say. 

So therefore, I would recommend to the patient that we get some home blood pressure readings to determine where his blood pressure likes to "live."  I will print out a pre-printed sheet of information about how to monitor home blood pressures.  It will say:

Purchase a good quality electronic, battery operated portable home blood pressure machine.  Make sure the cuff fits you before you purchase it.  Consumer Reports likes Omron brand and Reliant brand machines, though others might be just fine. 

Numbers: 

Systolic pressures above 140 are considered high.
Diastolic pressures above 90 are considered high.

Current guidelines indicate blood pressures for adults under age 70 should stay under 140/90.  For patients over 70, acceptable blood pressures should remain under 150/90.  

Start getting home blood pressure readings on a random basis, and write down the readings in a record book with dates and times. 

Specific instructions for making readings: 

--shoot for 3-4 random readings a week, but more is always better.  The concept of random is important here.  I want to know if blood pressures vary with different times of day.  I don't want to only get blood pressures in the morning when you are relatively dehydrated and haven't been moving much. 

--make sure you are always sitting quietly for at least five minutes before making a reading. 

--make sure both feet on the floor, no crossed legs.

--make sure no more than one thin layer of clothing maximum between your skin and the blood pressure cuff. 

--make sure you are not under unusual duress or in pain when getting the reading. 

I am interested in the long term average blood pressure reading over a couple of weeks.  That really tells me what I want to know.  If the average blood pressure is 150/90, then that is too high, and I am going to want to get that patient started on some type of first line treatment.  

I ask my patients to record their blood pressure readings on their smart phones (if they have one).  There are many applications ("apps") for smart phones which will store blood pressure readings and even graph them and calculate averages. 

(The current iPhone operating system comes with a built-in app called "Health" that will store observations such as blood pressure readings.) 


If the average home blood pressure is running 136/87 or so, I would consider that a "borderline" blood pressure range and we would work on non-pharmacologic interventions ("lifestyle interventions--see that post on this blog).  

If the average home blood pressure is running 120/84 or so, I would feel comfortable NOT intervening any further (or, if the patient is already on medication, I would not change anything).  

The beauty of home blood pressure monitoring is that it gives us highly useful, real-life numbers.  It also is incredibly more convenient that having the patient come in to the clinic, pay a $20 co-pay, and have us check their pressure.  If the patient is already on blood pressure medication, we can make adjustments in their dose based on home readings, and we don't need office visits every month for "fine tuning." 

If my patients are not sure about their home machine being accurate, I ask them to bring their machine in to the clinic and we check out their machine reading with what we get on our "official" clinic sphygmomanometer. 

Let's say that it is clear that the blood pressure readings at home or consistently in the office are just running too high.  Now what? 

There are some basic diagnostic tests that should be considered prior to treating hypertension.  Some of these tests are designed to make sure there are other causes of high blood pressure. 

Other causes of high blood pressure:

• elevated thyroid function
• kidney disease
• narrowed arteries supplying blood to the kidneys
• epinephrine (adrenaline) secreting tumors (exceedingly rare)
• other hormonal abnormalities
• excessive alcohol consumption (especially during withdrawal)
• medications such as stimulants (such as Ritalin for ADD)
• recreational drugs such as cocaine, speed, meth
• sleep apnea
• elevated pressures within the brain or skull

So when I come across someone with an apparent new diagnosis of hypertension, I will typically set up lab tests and other diagnostic steps to make sure none of these other issues is in play.  We will typically run a chemistry panel lab test to make sure that kidney function and electrolyte levels (sodium, potassium) are normal, a thyroid test to make sure we don't have an over-active thyroid, and we'll often run an electrocardiogram to make sure the electrical patterns of the heart are normal (that is, no evidence of heart enlargement or previous heart attack that might have been "silent"). 

The other issues are primarily derived by the history:  snoring with daytime sleepiness as indicators of sleep apnea, a frank alcohol history looking for excessive alcohol use, and other unusual symptoms that might suggest the rare possibility of an epinephrine-secreting tumor. 

Some of the tests might be done if we have more trouble than we anticipated in treating the hypertension.  If blood pressure is very hard to control, or if I am dealing with a very young person with no family history of hypertension, I'll consider doing an ultrasound of the blood flow through the renal arteries to make sure no blockages are fooling the kidneys into thinking the blood pressure is low. 

Treatment of Hypertension:

There is a relatively systematic approach to the treatment of high blood pressure:

Step 1:   Lifestyle changes--exercise, diet, and weight loss all have very positive effects on blood pressure control.  I'll definitely push this option for most people if they are motivated to work on these interventions and their blood pressures are not excessively elevated.

Sodium restriction is often effective in reducing blood pressure in some populations of people, but not everyone.  By sodium restriction, we mean keeping the daily salt intake to under 1500 mg daily.  This is actually not easy to do.  It takes some careful reading of food nutritional labels to get a feel for how much salt is taken in each day. 

Medications:  

There are many, many medications available for the treatment of high blood pressure.  However, they belong to a relatively limited number of families of medications.  Many factors come into play in the decision of which medication to try initially. 

Factors I consider:

--Side Effects:  I really don't want my patient to have noticeable side effects, given that high blood pressure has usually no symptoms. 

--Expense:  I want to use the least expensive option, generic if at all possible.

--Safety:  I want a medication that has a good safety profile.

--Effectiveness:  I want a medication that has been shown to not only reduce blood pressure, but ideally has good evidence that it reduces the effects of high blood pressure, such as heart attack and stroke, heart failure, and kidney damage. 

Medication Families:

Diuretics:  The two most commonly used medications in this family are hydrochlorothiazide (HYD-ro-KLOR-o-THY-uh-zide) or HCTZ for short, and chlorthalidone (klor-THAL-uh-doan).  These are officially "diuretics," in that they cause the kidneys to increase urine production, but they do NOT reduce blood pressure that way.  They work directly on reducing the "clench" of the muscles of the arterioles to "loosen them up" so that the overall resistance to blood flow is reduced.  Side effects of this group are rare--allergic reactions (especially if someone is already allergic to sulfa), rashes, lightheadedness, sun sensitivity, more frequent urination, potassium depletion, and rare muscle cramping are the usual ones I warn patients about.

Spironolactone is another diuretic-based antihypertensive medication that can work nicely.  Spironolactone (spuh-ROW-nuh-LAK-tone) has the added advantage in women of blocking hormone effects that might aggravate acne and excessive facial hair growth (hirsutism).  It also preserves potassium levels.   

Beta-Blockers:  This is a huge family.  There are many representatives of the beta-blocker family.  These medications work by blocking the effects of "beta-adrenergic" hormones--epinephephrine (adrenaline) being the primary one.  Common examples are propranolol (Inderal--which was the first on the market back in the 1980s), atenolol, metoprolol, carvedilol, nadolol, and several others.  Most of these are available generically.

Epinephrine works directly on small arteries and arterioles to constrict the muscles surrounding the vessels, thus increasing resistance to blood flow and increasing blood pressure.  By blocking the effects of epinephrine, the blood vessels stay "more open," and the blood flow is less restricted.  Beta-blockers work quite nicely most of the time.  They are largely well tolerated. 

However, they should not routinely be used in people who NEED the effects of adrenaline/epinephrine, such as asthmatics or brittle diabetics.  An asthma sufferer during an acute asthma attack NEEDS to use adrenaline-like rescue medication to open up their airways urgently, and having a medication on board that blocks the effects of adrenaline could make that rescue medication less effective.

A diabetic patient suffering from a rapidly-falling blood sugar will often notice symptoms of feeling shaky, rapid heart rate, and getting sweaty--symptoms caused by the release of epinephrine by the adrenal glands due to the rapidly falling blood sugar.  Blocking that epinephrine release effect could result in the diabetic not realizing their sugar levels are dropping quickly.  This does NOT mean we cannot use beta-blockers in diabetic patients; we simply have to keep this issue in mind and explain this to the patient.

Side effects of beta-blockers are related to the blockage of adrenaline/epinephrine:  slower heart rate, sometimes feeling lightheaded, sometimes fatigue (from loss of the adrenaline/epinephrine effect), sometimes decreased erectile function in males, and sometimes depression.  However, some people who are very anxious might benefit from blocking the excessive adrenaline surges that come with anxiety. 

Other benefits of beta-blockers:  They can reduce the frequency of migraine headaches. 

Calcium Channel Blockers:  These have been around for several decades.  The most commonly used members of this family are amlodipine, nifedipine, verapamil, and diltiazem.  In order for the smooth or involuntary muscle that surrounds the small arteries of the body to constrict, calcium ions have to be moved in and out of the muscle cell.  By blocking the "channels" that those calcium ions move through, the involuntary muscle cannot work, thus keeping the blood vessel more "open."

Side effects of calcium channel blockers are relatively rare, but could include faster heart rates, swelling in the feet and ankles, increased heartburn and acid reflux, headache, and lightheadedness.

Other benefits:  patients who suffer from Raynaud's Phenomenon--which is a rare "clamping-down" of the arterial blood supply to the fingers and/or toes due to cold temperatures or vibration--can benefit from being on nifedipine.  Also, calcium channel blockers are known to help reduce the frequency of migraine headaches.

ACE-Inhibitors:  Common members of this family are captopril (the first one that came available in the 1980s), lisinopril, benazapril, enalapril, and ramipril.  These medications work actually in the lung.  The kidneys make a hormone called renin (REE-nin) that helps regulate blood pressure.  If the kidneys think the blood pressure is too low, they make more renin.  Renin is converted in the lungs to a new hormone called angiotensin that then causes the smooth muscle of the small arteries and arterioles to squeeze down, increasing resistance and increasing blood pressure.  ACE-inhibitors block the transformation of renin to angiotensin, thus reducing the "squeeze" effect of angiotensin. 

Side effects of ACE-inhibitors can be headache, nausea, lightheadedness, allergic reactions, sudden facial swelling of a type called "angioedema," and a very odd, persistent, hacky cough.  They can rarely increase potassium levels.   

Other benefits of ACE-inhibitors:  This family of medications has been shown to help reduce the risk of kidney damage in diabetes patients.  In fact, most if not all diabetes patients who have normal kidney function should be considered to be on an ACE-inhibitor if they can, to protect their kidneys. 

Angiotensin-Receptor Blockers (ARBs):  We consider this family a sort of second generation of the ACE-inhibitor family.  These, as you can tell by their name, block the receptors for antiotensin on the involuntary muscle of the arterioles, thus keeping angiotensin from constricting the blood vessel.  Members of this family include losartan, candesartan, irbesartan, and others.  This family is relatively new, so fewer members of this family are available generically. 

Side effects of the ARBs include lightheadedness, dizziness, low blood pressure, worsening kidney function (if not monitored carefully), elevated potassium levels, and also, very rarely, the same odd hacky cough that can be seen with ACE-inhibitors.

There are several other less-commonly used groups of anti-hypertensive medications, but I'd estimate that 90% or more of our patients are controlled on the medications in the above five groups. 

Strategy:  I generally start with one medication at a low dose in one family, as a generic.  If that one seems to be well-tolerated, we monitor blood pressures on that medication for a few months.  Ideally, the patient is sending us his/her blood pressures from home monitoring periodically. If pressures are not well controlled, then we may move up the dose of the single medication somewhat. 

If still the blood pressure is not coming under adequate control, I'll usually recommend adding a low dose of a represtentative of a different family of anti-hypertensives.  The goal being to sort of hit the blood pressure from several "sides," and to keep the doses of each medication down to reduce side effects.  Many of these medications work together nicely as a "team."  Many are available combined together in generic "fixed combinations" such as lisinopril-hydrochlorothiazide in one tablet.  This allows the patient to take just one pill, for one price, while getting the benefits of two medications that are synergistic in their effects on blood pressure.

As long as my patient is sending me blood pressure readings fairly faithfully and regularly, we (the patient and I) can "tweak" the medications to reach our common goals of well-controlled blood pressure, minimized (or no) side effects, minimal cost, and maximal safety.  If the patient continues to lose weight, exercise, and eat healthily, it is not unheard-of for the patient to be allowed to come off the medications if the blood pressures are running great.