Many things can elevate blood pressure, from what you eat and drink to underlying medical conditions you may not know you have. Nearly half of U.S. adults (47.7%) meet the criteria for high blood pressure, defined as a systolic reading of 130 mm Hg or higher or a diastolic reading of 80 mm Hg or higher. Some causes are temporary, others are chronic, and understanding the difference helps you know what to address first.
Sodium and Fluid Balance
Salt is the single most well-known dietary driver of elevated blood pressure, and the mechanism is straightforward. When you consume more sodium than your kidneys can quickly excrete, your body holds onto extra water to dilute it. That temporarily expands your blood volume, which increases the output of your heart and pushes harder against artery walls. In a healthy system, your kidneys detect the higher pressure and flush the excess sodium out, bringing things back to baseline. But when this feedback loop is impaired, or when sodium intake stays consistently high, blood pressure remains elevated instead of resetting.
People vary in how sensitive they are to salt. Some can eat a high-sodium meal and see little change in their readings, while others experience a meaningful spike. This trait, called salt sensitivity, is influenced by genetics, age, and kidney function. It tends to become more pronounced as you get older.
Excess Body Fat
Carrying extra weight, particularly around your midsection, raises blood pressure through several overlapping pathways. Fat that surrounds your blood vessels is metabolically active. It produces signaling molecules, including inflammatory compounds and hormones like leptin, that directly influence how tightly your blood vessels constrict. It also releases angiotensin II, a molecule that narrows blood vessels and tells your kidneys to retain sodium. Over time, this chronic low-grade inflammation and increased vascular resistance keep your blood pressure persistently higher than it would otherwise be.
Stress and the Nervous System
When you’re stressed, your body releases a surge of hormones that make your heart beat faster and your blood vessels constrict. This is the classic fight-or-flight response, and it raises blood pressure quickly. In isolation, a single stressful event produces a temporary spike that resolves once the threat passes. The concern is chronic stress: when the hormonal surge repeats day after day, it contributes to sustained elevation over time and can accelerate damage to artery walls.
Alcohol Beyond Moderate Amounts
Alcohol’s effect on blood pressure depends heavily on how much and how often you drink. Having more than three drinks in a single sitting raises blood pressure in the short term. Heavy use, defined as more than three drinks a day for women or four for men, is linked to sustained hypertension. Binge drinking (four or more drinks in two hours for women, five for men) creates sharp spikes that stress the cardiovascular system even if your overall weekly intake seems moderate. Staying within one drink a day for women and two for men is the general threshold considered lower risk.
Caffeine
Caffeine raises both systolic and diastolic blood pressure, typically peaking around 45 to 60 minutes after consumption. The size of the spike varies depending on your baseline. In one study, 89% of people with diagnosed hypertension crossed into the hypertensive range after a standard dose of caffeine, compared to 19% of those with high-normal readings. If you already run high, your morning coffee or energy drink produces a proportionally larger bump. For most people, the effect is temporary, but stacking multiple caffeinated drinks throughout the day can keep your readings elevated for hours.
Common Medications and Supplements
Several medications you might take for completely unrelated reasons can push your blood pressure up. Some of the most common culprits:
- Pain relievers (NSAIDs): Over-the-counter options like ibuprofen (Advil) and naproxen (Aleve) cause your body to retain sodium and fluid, raising blood pressure. This is especially relevant if you take them regularly for chronic pain or arthritis.
- Decongestants: Ingredients like pseudoephedrine and phenylephrine, found in many cold and sinus products, work by narrowing blood vessels in your nasal passages. That narrowing effect isn’t limited to your nose.
- Hormonal birth control: Pills and patches containing hormones raise blood pressure in some people. Most carry a warning about this side effect.
- Antidepressants: Several classes, including SSRIs, tricyclics, and MAO inhibitors, can elevate readings.
- ADHD stimulants: Medications like methylphenidate (Ritalin, Concerta) increase heart rate and blood pressure as part of their mechanism.
- Herbal supplements: Licorice root, ginseng, guarana, and ephedra (ma-huang) all have blood pressure-raising effects that many people don’t anticipate from “natural” products.
Illicit stimulants like cocaine, methamphetamine, and ecstasy also produce dangerous, sometimes extreme blood pressure spikes.
Sleep Apnea
Obstructive sleep apnea is one of the most underdiagnosed causes of high blood pressure. An estimated 50% of people with hypertension also have sleep apnea. During sleep, the airway repeatedly collapses, cutting off oxygen for seconds at a time. Each episode triggers a burst of adrenaline-like hormones that constrict blood vessels. These surges happen dozens or even hundreds of times per night, and the hormonal changes persist into the daytime, keeping blood pressure elevated around the clock.
There’s also a fluid-redistribution effect. When you lie down, fluid that pools in your legs during the day shifts upward toward your neck and chest. In people with hypertension, this fluid shift narrows the upper airway more dramatically, worsening the apnea, which in turn drives blood pressure even higher. This creates a self-reinforcing cycle that can lead to resistant hypertension, the kind that doesn’t respond well to standard medications.
Kidney and Hormone Disorders
When high blood pressure is caused by an identifiable medical condition, it’s called secondary hypertension. The kidneys and adrenal glands are the most frequent sources.
Kidney-Related Causes
Your kidneys are the organs responsible for regulating how much sodium and fluid stay in your bloodstream, so any disease that impairs kidney function tends to raise blood pressure. Diabetes is the most common offender: over time, high blood sugar damages the kidneys’ filtering units, reducing their ability to excrete sodium efficiently. Polycystic kidney disease, an inherited condition where cysts crowd out functional kidney tissue, does the same. Narrowing of the arteries that supply blood to the kidneys (renovascular hypertension) tricks the kidneys into thinking blood pressure is too low, prompting them to retain even more fluid.
Adrenal and Thyroid Causes
The adrenal glands sit on top of your kidneys and produce hormones that directly control blood pressure. In a condition called aldosteronism, the adrenals overproduce a hormone that forces the kidneys to hold onto salt and water. Cushing syndrome involves excess cortisol, which has a similar effect. A rare adrenal tumor called a pheochromocytoma floods the body with adrenaline, causing dramatic spikes or sustained high readings. Both an overactive and underactive thyroid gland can raise blood pressure, as can overactive parathyroid glands, which elevate calcium levels in the blood.
Age and Sex
Blood pressure tends to rise with age regardless of lifestyle. Among U.S. adults aged 18 to 39, about 23% have hypertension. That jumps to 52.5% for ages 40 to 59 and reaches 71.6% for people 60 and older. Arteries gradually stiffen over decades, requiring the heart to pump harder to move the same volume of blood.
Men are more likely to have high blood pressure than women in younger and middle age (30% vs. 16.4% among 18- to 39-year-olds, 55.9% vs. 49% among 40- to 59-year-olds). After 60, the gap between men and women essentially disappears, likely reflecting hormonal changes after menopause that remove the protective effect of estrogen on blood vessel flexibility.