Aspirin
Should I Take Aspirin If I Have High Blood Pressure?
Aspirin isn’t commonly known to affect blood pressure. But it does come with a higher risk of bleeding.
There are a few groups of people who may benefit from taking low-dose aspirin (81 mg per day). This includes people who’ve previously had a heart attack or stroke. But you shouldn’t start aspirin without talking to your healthcare provider first.
The risks of taking aspirin may outweigh the benefits in many people. This usually includes people who haven’t had a heart attack or stroke and are at low risk of heart disease. It also includes people who have a high risk of bleeding.
Hypertension (high blood pressure) is a common medical condition. It affects one-third of U.S. adults. Although certain groups of people — including older adults and African Americans — are more likely to experience hypertension, it’s a health condition that can happen to anyone.
Most people with hypertension don’t have symptoms. But it can lead to serious medical problems, including heart disease or a stroke, if it isn’t treated. These are some of the most common causes of death in the U.S.
Many medications treat high blood pressure, and you may have wondered if aspirin is one of them. The answer, though, is somewhat complicated.
Overall, aspirin hasn’t been found to consistently lower blood pressure. But some research shows that low-dose aspirin (81 mg per day) may lower blood pressure when it’s taken before bedtime. Researchers aren't exactly sure why this occurs, but it might be because certain blood pressure-raising hormones are more active overnight.
Still, low-dose aspirin isn’t a recommended medication for lowering blood pressure in people with hypertension. Many other medications are better studied and have been proven to lower blood pressure. If you have hypertension, your healthcare provider will likely recommend a medication that's been FDA approved to treat it. Some examples include:
Thiazide diuretics, like hydrochlorothiazide and chlorthalidone
Angiotensin-converting enzyme (ACE) inhibitors, like lisinopril (Zestril), enalapril (Vasotec), and benazepril (Lotensin)
Angiotensin II receptor blockers (ARBs), like losartan (Cozaar), valsartan (Diovan), irbesartan (Avapro)
Calcium channel blockers, like amlodipine (Norvasc), verapamil, diltiazem (Cardizem)
Beta blockers, like atenolol (Tenormin), carvedilol (Coreg), and metoprolol (Lopressor)
Aspirin is part of a group of medications called non-steroidal anti-inflammatory drugs (NSAIDs). It works by blocking two enzymes (proteins) — cyclooxygenase-1 and -2 (COX-1 and COX-2). COX-1 and COX-2 are responsible for making prostaglandins. Prostaglandins are chemicals your body releases when you experience an injury or your cells get damaged. Your body may respond to prostaglandins in a few ways, including:
Inflammation
Swelling
Pain
Fever
By blocking COX-1 and COX-2, aspirin helps relieve these symptoms.
Low-dose aspirin can also help prevent cardiovascular disease. Cardiovascular disease is a group of medical conditions that affect the heart and blood vessels. Having cardiovascular disease makes it more likely to have a heart attack or stroke.
Low-dose aspirin can help some people avoid these life-threatening events by preventing blood clots. It does this by preventing platelets — blood cells that help form clots to stop bleeding — from clumping together. While clotting can be a good thing, abnormal clotting can prevent blood from reaching your heart or brain.
Blood clots in your heart can lead to a heart attack, and clots in your brain can cause a stroke. So for some people, taking low-dose aspirin daily is beneficial.
Always talk to your healthcare provider before starting low-dose aspirin. Even though it’s available over the counter, the risks outweigh the benefits for people who don’t really need it. There are a few groups of people that may benefit from low-dose aspirin, so your healthcare provider may still recommend it. More on this next.
The U.S. Preventive Services Task Force (USPSTF) recommends that healthcare providers consider daily low-dose aspirin to prevent cardiovascular disease in certain groups of people. These groups include:
People who’ve had a heart attack, stroke, atrial fibrillation, or vascular stenting in the past.
Adults, age 40 to 59, who have a high risk of cardiovascular disease and a low risk of bleeding. Your healthcare provider can help you use a risk estimator to evaluate your chances of developing cardiovascular disease. They can also talk to you about whether you have a higher bleeding risk.
If you think you qualify for low-dose aspirin treatment, talk to your healthcare provider. They can help you figure out if you’re a good candidate based on your medical history, personal preferences, and risk factors for cardiovascular disease.
Preeclampsia is a medical condition where high blood pressure and abnormally high protein in the urine occurs during pregnancy. In severe cases, it can lead to organ damage in the pregnant mother and growth problems in the developing baby.
Preeclampsia can also put the pregnant mother at risk of heart problems in the future. A large review of over 250,000 pregnant women with preeclampsia found that having preeclampsia made you twice as likely to have heart disease or a stroke later in life. Because of this, the USPSTF recommends starting low-dose aspirin after 12 weeks of pregnancy in people who are at high risk of preeclampsia.
People who have diabetes, chronic hypertension, or who’ve had preeclampsia in a previous pregnancy are at the highest risk for preeclampsia. Additional risk factors include:
Pregnancy with more than one baby
People who’ve used assisted reproductive technology (ART) to become pregnant
Kidney disease
Autoimmune disease, like lupus
The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine have similar recommendations. They recommend low-dose aspirin starting between 12 and 28 weeks of pregnancy in pregnant women at high risk of preeclampsia. They specify the optimal time to start low-dose aspirin is before 16 weeks.
Keep in mind there are many other risk factors for preeclampsia besides what’s listed here. If you’re pregnant and unsure if you should take aspirin, talk to your OB-GYN physician. They can help you decide whether low-dose aspirin is a good option for you during pregnancy.
Most people are taking low-dose aspirin to prevent heart attack and stroke, or if they’re experiencing preeclampsia. But there’s also a chance your healthcare provider might recommend low-dose aspirin for other reasons. For example, low-dose aspirin may help prevent repeat pregnancy loss.
But no matter your situation, don’t start low-dose aspirin without talking to your healthcare provider. It can be hard to figure out on your own whether you need low-dose aspirin. Your provider can help you decide if it’s beneficial.
Aspirin can have both mild and more severe side effects. Mild side effects may include:
Nausea and upset stomach
Loss of appetite
Headache
More serious side effects include:
Kidney problems
Stomach ulcers
Reye’s syndrome in children
Skin reactions
Keep in mind that certain groups of people are at higher risk of side effects when taking aspirin. For example, people at higher risk of bleeding with aspirin include those who smoke, take other medications that can cause bleeding, or are 60 years or older.
If you have any signs of serious side effects from aspirin, like unusual bruising, blood in your stool or a painful, peeling rash, seek immediate medical care.
Aspirin isn’t considered a first-choice option for treating high blood pressure. But it can be a helpful medication for preventing heart-related problems (like heart attack) and stroke in some people. This includes people who’ve had a prior heart attack or stroke. It also includes adults aged 40 to 59 that have a low risk of bleeding and a high risk for cardiovascular disease.
But for many people, the risks of aspirin outweigh its benefits. This includes people over 60 years old who have never had a heart attack or stroke. It also includes people at a high risk for bleeding. Talk to your healthcare provider if you’re wondering if you should take aspirin. They can help you weigh the risks and benefits.
American College of Cardiology. (n.d.). ASCVD risk estimator.
American Heart Association. (2022). New USPSTF guidance: Continue to take low-dose aspirin if you have a history of heart attack, afib, stroke or vascular stenting.
Bryant, A. S., et al. (2021). Low-dose aspirin use for the prevention of preeclampsia and related morbidity and mortality. The American College of Obstetricians and Gynecologists.
Centers for Disease Control and Prevention. (2021). Facts about hypertension.
Costa, A. C., et al. (2017). Aspirin and blood pressure: Effects when used alone or in combination with antihypertensive drugs. Revista Purtuguesa de Cardiologia.
Hermida, R. C., et al. (2003). Administration time-dependent effects of aspirin on blood pressure in untreated hypertensive patients. Hypertension.
Hermida, R. C., et al. (2005). Aspirin administered at bedtime, but not on awakening, has an effect on ambulatory blood pressure in hypertensive patients. Journal of the American College of Cardiology.
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National Institutes of Health. (2021). Low-dose aspirin may improve pregnancy chances for women with one or two prior miscarriages.
Obstetrics & Gynecology. (2018). ACOG committee opinion No. 743: Low-dose aspirin use during pregnancy.
U.S. Food and Drug Administration. (2021). High blood pressure — understanding the silent killer.
U.S. Preventive Services Task Force. (2022). Aspirin use to prevent cardiovascular disease. JAMA.
U.S. Preventive Services Task Force. (2022). Aspirin use to prevent cardiovascular disease: Preventive medication.
U.S. Preventive Services Task Force. (2021). Aspirin use to prevent preeclampsia and related morbidity and mortality. JAMA.
Vane, J. R., et al. (2003). The mechanism of action of aspirin. Thrombosis Research.
Whelton, P. K., et al. (2018). 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association task force on clinical practice guidelines. Hypertension.
World Health Organization. (2021). Cardiovascular diseases (CVDs).
Wu, P., et al. (2017). Preeclampsia and future cardiovascular health. Circulation: Cardiovascular Quality and Outcomes.
Whether you were recently diagnosed with high blood pressure, want to reduce your risk, or want to better understand your treatment options, our free 7-day guide can help.
