Blood Pressure Still High on Medication? What It Can Mean
You take your pills every morning. You have cut back on salt. Then the cuff flashes 148/92 again. If that sounds familiar, you have plenty of company: nearly half of U.S. adults have high blood pressure, and only about 1 in 4 of them have it under control, according to the CDC.
Key takeaways
A reading that stays above your target while you take medicine is worth raising with your care team, not something to live with quietly.
Common causes include how the reading is taken, missed doses, salt, some over-the-counter medicines and conditions such as sleep apnea.
When blood pressure stays high on several medicines, doctors may look for hidden causes or adjust the combination.
ZENITH (NCT07181109) is a Phase 3 study of an investigational medicine for adults whose blood pressure stays high despite two or more medicines.
What counts as "still high"?
The American Heart Association groups readings into these categories:
Normal: below 120 on top and below 80 on the bottom
Elevated: 120 to 129 on top, with the bottom number still below 80
Stage 1 hypertension: 130 to 139 on top, or 80 to 89 on the bottom
Stage 2 hypertension: 140 or higher on top, or 90 or higher on the bottom
Severe hypertension: higher than 180 on top and/or higher than 120 on the bottom
The 2025 AHA and ACC guideline recommends a goal below 130/80 for most adults. Your own target may differ based on your age and health, so ask your clinician which number you are aiming for. If your home readings regularly sit above it even though you take your medicine as prescribed, your blood pressure is not controlled yet.
When a reading needs urgent attention
If your blood pressure is higher than 180/120, wait one minute and measure again. If it is still that high and you have chest pain, shortness of breath, back pain, numbness, weakness, vision changes or trouble speaking, call 911. If you have no symptoms, contact your healthcare professional promptly. This guidance comes from the American Heart Association.
Why can blood pressure stay high even with medicine?
There is rarely one single reason. These are the ones clinicians check most often:
1. The reading itself
A cuff that is too small, talking during the measurement, a full bladder or a coffee 20 minutes earlier can all push numbers up. Some people also read higher only in the clinic, which is known as the "white coat" effect. Home readings taken the way the CDC recommends give your doctor a clearer picture.
2. Doses that get skipped or stretched
Side effects, cost or simply forgetting can lead to missed doses. Cleveland Clinic notes that not taking medicine as directed plays a part in a large share of hard-to-control cases. Telling your doctor about side effects is useful information, not a confession. There is often another option.
3. Salt, alcohol and other everyday factors
Much of the sodium people eat comes from packaged and restaurant food, not the salt shaker. Regular alcohol, poor sleep and weight gain can also work against medication.
4. Other medicines and supplements
Pain relievers such as ibuprofen and naproxen (NSAIDs) and some decongestants can raise blood pressure. Bring a full list, including over-the-counter products, to your appointment.
5. A condition that drives blood pressure up
Sleep apnea, primary aldosteronism (an adrenal gland that makes too much of the hormone aldosterone), chronic kidney disease and narrowing of the kidney arteries can all keep blood pressure high. Doctors call this secondary hypertension, and treating the cause can make a real difference.
6. The combination may need adjusting
Many people need two or three medicines from different classes. When blood pressure stays above goal on three medicines, including a diuretic ("water pill"), at the best tolerated doses, the American Heart Association calls it resistant hypertension.
Questions to bring to your next appointment
What blood pressure target should I aim for, and how close am I?
Could my home monitor or cuff size be affecting my readings?
Should I be checked for sleep apnea, aldosterone problems or kidney issues?
Are any of my other medicines or supplements raising my blood pressure?
Would a different combination, or a combined single pill, make my routine easier?
Are there clinical research studies I might be able to join?
For a deeper look at why the readings matter beyond the numbers, see what high blood pressure does to your heart, brain and kidneys.
Already taking two or more blood pressure medicines? See if the ZENITH study may be an option.
Check eligibility
Where clinical research comes in
Every blood pressure medicine used today was once tested in clinical trials. Researchers are now studying approaches that work in a different way from daily pills. One of them is zilebesiran, an investigational medicine designed to lower the liver's production of angiotensinogen, a protein at the start of a hormone chain that raises blood pressure.
Study snapshot: ZENITH (NCT07181109)
What is being studied
Zilebesiran, an investigational medicine given as an injection under the skin every six months, added to a person's usual blood pressure medicines.
Compared with
Placebo (an injection with no active medicine). Participants keep taking their regular blood pressure medicines either way.
Main question
Whether zilebesiran lowers the risk of serious heart and blood vessel events, such as heart attack, stroke, heart failure events or death from cardiovascular causes.
Size and scope
A global Phase 3 study planned to include about 11,000 adults in 35 countries.
Who may be a fit
Adults whose blood pressure stays high despite two or more blood pressure medicines, and who have established cardiovascular disease or high cardiovascular risk.
Local study sites
Research sites working with HEKMA include Birmingham, AL; Evansville, IN; Phoenix, AZ; and San Antonio, TX.
ZENITH is looking at more than blood pressure readings. Its main goal is to find out whether adding zilebesiran lowers the chance of heart attacks, strokes and heart failure events. That is why it enrolls people with established cardiovascular disease or high cardiovascular risk. If you are unsure which group you might fall into, read what high cardiovascular risk means.
Who the study is looking for
Based on the study's listed criteria, people who may be a fit are adults who:
Have a top (systolic) blood pressure number that stays roughly between 140 and 180 despite treatment
Take two or more blood pressure medicines on a steady schedule, one of which is a diuretic
Have had a heart or blood vessel problem (for example a heart attack, stent, bypass surgery, stroke, or narrowed neck or leg arteries), or have a health profile that puts them at high cardiovascular risk
Some people will not be able to take part, for example those with a known secondary cause of high blood pressure, severe kidney disease, a heart attack or stroke in the past 60 days, a certain type of heart failure, very uncontrolled diabetes, or who are pregnant or breastfeeding. The study team reviews every person individually.
What happens if you check your eligibility
Answer a short online questionnaire. It covers your diagnosis, medicines and heart history.
Hear from the study team. If you look like a possible match, someone from a nearby research site contacts you to answer questions.
Review the informed consent form. It explains the visits, possible risks, the chance of receiving placebo and your rights. Take it home and discuss it with family or your doctor.
Attend a screening visit. Tests confirm whether you meet all the criteria. You can stop at any point, before or after joining.
Keep taking your medicine
Do not stop or change any blood pressure medicine because of this article. Any change should be made with your healthcare professional.
Want to understand how trials work before you decide? Our guide to clinical research for people on two or more blood pressure medicines walks through placebo, randomization and consent.
Frequently asked questions
Is it normal for blood pressure to stay high on medication?
It is common, but it is not something to accept. It often means the reading technique, the dose, the combination of medicines or an underlying cause needs a closer look with your healthcare professional.
What is resistant hypertension?
The American Heart Association defines resistant hypertension as blood pressure that stays above goal despite three blood pressure medicines of different classes, usually including a diuretic, at the best tolerated doses, or blood pressure that needs four or more medicines to control.
What is the ZENITH study?
ZENITH (NCT07181109) is a global Phase 3 clinical trial testing whether zilebesiran, an investigational injection given every six months, lowers the risk of serious cardiovascular events when added to usual blood pressure treatment. It is compared with placebo.
Do I have to stop my current blood pressure medicines to join?
No. In ZENITH, the study medicine or placebo is added to the blood pressure medicines you already take. Never stop a medicine on your own.
Does filling out the questionnaire sign me up for the study?
No. The questionnaire only helps the study team see whether you might be a fit. Joining happens only after you review and sign the informed consent form, and you can withdraw at any time.