By Katie E. Golden, MD

What do those numbers even mean?

Hypertension, or high blood pressure, is one of the most common diseases in the United States. Many doctors counsel their patients on the need for good blood pressure control without explaining the fundamentals of the condition. So before we get into the nitty-gritty, let’s start with a simple definition. 

Blood pressure is quite simply a measure of the pressure exerted on the walls of the blood vessels that carry blood from the heart to the rest of the body.  This measurement includes two numbers: systolic pressure and diastolic pressure. When we say a blood pressure is 120/80, we mean the systolic pressure is 120 mmHg and the diastolic pressure is 80 mmHg. The systolic number represents the pressure when the heart is actively pumping blood through the vessels (the ‘squeeze’ phase), and the diastolic pressure reflects when the heart is relaxed and filling back up with blood (the ‘recovery’ phase). 


Why do care so much about blood pressure?


At the end of the day, our blood vessels are the critical plumbing system of the body that keeps blood flowing to all our organs. We will spare you a trip back to physics class, but some of you may remember how the resistance in a pipe affects how effectively fluid can flow through those pipes. A blood pressure that is too high or too low will affect how well our vessels can deliver blood (and oxygen) to the rest of our body.


Most patients are familiar with the way chronically elevated blood pressure can be detrimental to our health. Our critical organs (the heart, brain, and kidneys) are all affected when our blood pressure is persistently elevated over time. This can lead to a spectrum of diseases – coronary artery disease, congestive heart failure, stroke, kidney disease – the list goes on. This is why doctors want to pay close attention to helping their patients maintain a healthy range of blood pressures.


So what causes our blood pressure to be elevated?


Our blood pressure can rise transiently in response to a specific situation, or can be elevated more chronically secondary to certain diseases, diet, lifestyle, even aging. The latter is more important for long term health.


Temporary elevations in blood pressure can result from stressful life circumstances such as pain, an argument with a friend, pressure on the job, grief or depression, waiting for your coffee at Starbucks. You get the picture. This is normal, expected, and a part of life. 


More sustained elevations in blood pressure can result from chronic conditions such as aging (our blood vessels naturally get stiffer as we get older), a diet high in salt (which leads to retention of fluid and thus increased volume in the blood vessels), a diet high in cholesterol (the cholesterol deposits in the walls of our blood vessels and thus makes them stiffer), hormonal changes, diseases of the brain or kidney – the list goes on. It is this long term hypertension, however, that can lead to disease.


The take-home point for our patients here is that, while we can’t always control the day to day circumstances that lead to fluctuations in our blood pressure, the main goal is a relatively well-controlled blood pressure over time. It is also important to point out that as we age, and our blood vessels naturally get stiffer, it is normal to have a gradually increasing baseline pressure over time. In other words, healthy blood pressure for a 20-year-old is not the same number as healthy blood pressure for a 70-year-old, and so a ‘healthy range’ is relative to the patient and their chronic medical conditions.


So what does it mean that my blood pressure was high in the ER?


We are no stranger to high blood pressure readings in the emergency department. The circumstances of an ER visit lend themselves to times of physiologic stress that tend to raise a patient’s blood pressure, whether it be pain from their current condition, the natural anxiety that comes with a personal medical emergency, frustration over long wait times, hunger, etc. For this reason, ER doctors tend not to overreact to high blood pressure readings, as we understand that this will likely normalize when the patient leaves the ER. (Interestingly, in times when we used to be more aggressive about lowering blood pressure in the ER, the research found that this led to dangerously low blood readings after discharge that was equal and if not more dangerous than high blood pressure, so experts have since provided guidelines to avoid this practice). 


There are a few circumstances when we will give the patient medicine to bring down their blood pressure, and that is only when they are in the ER for a condition that could stand to worsen with elevated blood pressures (these conditions are rare, like bleeding in the brain or a heart attack, and we will leave those topics for a different day). 


Do not be dismayed if the checks of your vital signs in the ER revealed higher blood pressure than you are used to seeing in your regular doctor’s office or home blood pressure cuff readings. More importantly, don’t let the anxiety over these numbers raise your pressure even more. If your ER doctor elects not to give you blood pressure medication in the ED, this is likely a well thought out decision to protect you from dangerously low blood pressure. The best practice is to take your prescribed medicines when you return home, continue to monitor your blood pressure if that has been recommended by your regular doctor, and schedule a follow-up appointment if your blood pressure remains elevated or you have concerns about poorly-controlled hypertension.


Should I consider coming to the ER if my blood pressure at home is too high?


We often see patients who come in out of concern for elevated blood pressure readings at home. In many cases, patients can save themselves the time, money, and anxiety of an ER visit and simply schedule an appointment with their regular doctor to discuss their blood pressure trends and medications. There are circumstances, however, when we would recommend coming to see us for an evaluation.


  • More important than the actual number is your symptoms: if your blood pressure is accompanied by a severe headache, chest pain, shortness of breath, or stroke-like symptoms (confusion, vision changes, difficulty speaking, a droopy face, weakness on one side of the body, or numbness in the face or extremities), then please call 911.
  • If you have no symptoms with your high readings, then typically we recommend you take your prescribed medications, do your best to alleviate any current stressors, and recheck your pressure after you have given your body a chance to relax and re-equilibrate (probably about 30-60 minutes).
  • If your blood pressure remains persistently elevated with systolic blood pressure over 200 or diastolic blood pressure over 120, sustained pressure this high can potentially be dangerous and you should consider coming to see us.
  • If you are not experiencing any symptoms and questioning whether you need to come to the ER, don’t hesitate to call your regular doctor and them, or their triage nurse may be able to help direct you.