A common cold can nudge your blood pressure upward, though the bump is usually modest and temporary in otherwise healthy people. The infection itself triggers an inflammatory response that stresses the cardiovascular system, and many of the over-the-counter drugs people reach for to treat cold symptoms carry their own blood-pressure effects. For most people the rise is small enough to go unnoticed, but if you already manage hypertension, the combination of the illness and its remedies deserves closer attention than it typically gets.
How the Infection Itself Affects Blood Pressure
When a virus invades your upper respiratory tract, your immune system launches a counterattack that does not stay neatly confined to your nose and throat. Immune cells release signaling molecules, including interleukin-6, tumor necrosis factor, and interleukin-1β, that promote inflammation throughout the body. In severe cases of influenza, this cascade can escalate into what researchers call a cytokine storm, driving widespread vascular effects including leaky blood vessels and tissue damage.1PubMed Central. Cytokine and Endothelial Activation Patterns Related to Severe and Non‐Severe Respiratory Viral Infections A run-of-the-mill cold is far less dramatic than full-blown influenza, but the same general process occurs on a smaller scale. Your body ramps up sympathetic nervous system activity, your heart rate ticks up, and your blood vessels may constrict slightly in response to circulating inflammatory signals.
Multiple viral infections have been linked to endothelial dysfunction, where the thin lining of blood vessels becomes inflamed and less able to regulate blood flow properly.2PubMed Central. Viral Endothelial Dysfunction: A Unifying Mechanism for COVID-19 When those vessel walls are irritated, they lose some of their ability to relax on cue, which tends to push blood pressure up. In a healthy person with normal baseline readings, this effect is typically small enough that they never notice it. But in someone whose vessels are already stiffened by age, diabetes, or chronic hypertension, even a small additional insult can produce a measurable rise.
Oral Decongestants and Blood Pressure
If you have ever taken a cold tablet to unstuff your nose, you have probably swallowed pseudoephedrine or phenylephrine. These drugs work by narrowing blood vessels in the nasal passages so swelling goes down and air can pass through. The concern is that the same vessel-narrowing effect might not stay local and could raise pressure system-wide.
The evidence on this is more reassuring than most people expect. A Cochrane review pooling data from several randomized trials found that oral decongestants may have little to no effect on systolic blood pressure compared with a placebo, with a mean difference of less than 1 mmHg, though the review characterized its own certainty as very low. For diastolic pressure the picture was similar, with essentially no meaningful change detected.3Cochrane Library. Effect of adrenergic agonist oral decongestants on blood pressure One trial specifically tracked patients who already had controlled hypertension and were taking pseudoephedrine for four weeks. Average systolic and diastolic readings in the drug group were virtually identical to the placebo group throughout the study.4PubMed. Does pseudoephedrine increase blood pressure in patients with controlled hypertension?
Phenylephrine, the decongestant that replaced pseudoephedrine on many pharmacy shelves because it cannot be used to make methamphetamine, tells a similar story at standard doses. A systematic review and meta-analysis found no consistent effect on heart rate or blood pressure for phenylephrine doses of 25 mg or less.5PubMed. Efficacy and safety of oral phenylephrine: systematic review and meta-analysis At the typical over-the-counter dose of 10 mg, it appears well tolerated in most people, though doses above 15 mg can start pushing pressure upward.6PubMed Central. Potential cardiovascular adverse events when phenylephrine is combined with paracetamol: simulation and narrative review In practice, the people at risk are those who double up on combination products or take extra doses when the first one does not seem to work fast enough. Two multi-symptom cold products taken together could push you well beyond the single-ingredient dose.
Do Nasal Sprays Avoid the Problem?
A reasonable follow-up question is whether switching to a topical nasal spray, such as oxymetazoline, side-steps the blood pressure concern by keeping the drug local. A randomized, double-blind trial tested intranasal oxymetazoline, phenylephrine, lidocaine with epinephrine, and saline. None of the active drugs raised mean arterial pressure by a clinically or statistically significant amount compared with plain saline.7PubMed Central. Effect of Intranasal Vasoconstrictors on Blood Pressure: A Randomized, Double-Blind, Placebo-Controlled Trial That is reassuring for short-term use. The catch with nasal sprays is a different one: rebound congestion if you use them beyond three or four days, which can trap you in a cycle of worsening stuffiness and more spray. The blood pressure concern with sprays, at least during a typical cold, appears to be minimal.
Pain Relievers You Might Not Suspect
Decongestants get most of the suspicion, but the pain relievers people take alongside them deserve scrutiny too. Ibuprofen and naproxen, both nonsteroidal anti-inflammatory drugs, are staples for cold-related headaches, sore throats, and fevers. These drugs affect the kidneys by reducing blood flow and promoting sodium retention. In people who are sensitive to salt, that retained sodium can push blood pressure higher.8PubMed Central. The effect of nonsteroidal anti-inflammatory drugs on blood pressure in patients treated with different antihypertensive drugs
The effect matters most for people already on blood pressure medication. Some antihypertensive drugs, particularly ACE inhibitors and diuretics, work partly through the same kidney pathways that NSAIDs interfere with. Taking ibuprofen for a week of cold symptoms can blunt the effectiveness of those medications, essentially undoing some of the blood-pressure-lowering benefit you rely on daily. For the occasional two-day headache, the effect is unlikely to be dramatic. But a lingering cold that has you reaching for ibuprofen three times a day for a week starts to matter. Acetaminophen (paracetamol) is often suggested as a safer alternative for people managing hypertension, though it is not completely free of blood pressure effects at high and sustained doses.
Sleep Disruption During Illness
Anyone who has spent three nights coughing, mouth-breathing, and tossing around knows that a cold wrecks sleep quality. This matters for blood pressure because sleep loss on its own raises it. A systematic review found that total sleep deprivation increased systolic and diastolic blood pressure in young adults regardless of body position, and blunted the normal nighttime dip in pressure that your cardiovascular system depends on for recovery.9PubMed Central. The association between sleep deprivation and arterial pressure variations: a systematic literature review
During a cold, sleep is rarely eliminated entirely, but it is fragmented and shallower. Congestion forces mouth breathing, which worsens snoring and can aggravate sleep apnea in people who already have it. The sympathetic nervous system, already revved up by the infection, does not get the overnight downshift it normally would. This is one of the less obvious ways a cold raises pressure: not through any single dramatic mechanism, but through several nights of poor rest compounding the immune system’s existing stress response.
The Cardiovascular Risk Window After a Respiratory Infection
Perhaps the most striking finding about respiratory infections and the heart is what happens in the days immediately after you get sick. A large linked-data analysis from Scotland found that a confirmed respiratory infection made people roughly six times more likely to have a heart attack or stroke in the three days following infection. The elevated risk from influenza and pneumonia persisted for up to a week for heart attacks and up to a month for strokes.10European Respiratory Journal. Laboratory-confirmed respiratory infections as triggers for acute myocardial infarction and stroke: a self-controlled case series analysis of national linked datasets from Scotland
This does not mean that catching a cold puts you in immediate cardiac danger. The absolute risk remains low for most people, and the Scotland study focused on laboratory-confirmed infections, which tend to be more severe than the average sniffle that never gets tested. Still, the data suggest that the cardiovascular system is genuinely vulnerable during acute infection, and that vulnerability is most pronounced in people who already have underlying heart disease or significant risk factors. If you manage hypertension and develop a respiratory infection with fever and significant malaise, it is a reasonable time to keep an eye on your blood pressure readings at home and to be aware that chest pain or sudden neurological symptoms warrant urgent attention.
Dehydration and Fluid Shifts
A cold does not usually cause the dramatic fluid loss that a stomach virus does, but mild dehydration is still common. Fever increases fluid loss through sweat, mouth breathing dries out mucous membranes, and people who feel lousy tend to drink less than usual. The relationship between hydration and blood pressure is not a simple one-way street, though. Severe dehydration tends to drop blood pressure by reducing blood volume. Mild dehydration, on the other hand, can activate compensatory hormonal pathways, including the renin-angiotensin system, that constrict blood vessels and retain sodium in an effort to maintain pressure. Research has shown associations between hydration parameters and hypertension status, with hypertensive individuals tending to have altered fluid distribution compared with people with normal blood pressure.11PubMed Central. Assessment of Hydration Status and Blood Pressure in a Tertiary Care Hospital at Al-Khobar
The practical takeaway is straightforward: staying hydrated during a cold helps your body manage blood pressure more smoothly. You do not need to force gallons of water, but keeping up with regular fluid intake, especially if you are running a fever, removes one variable from the equation.
Home Remedies That Can Quietly Raise Blood Pressure
When people feel sick, they often turn to herbal teas and traditional remedies, and most of these are harmless. Licorice root is the notable exception. Licorice-containing teas and supplements are sometimes marketed for sore throats and respiratory complaints, and many people drink them liberally during a cold without realizing the cardiovascular implications. The active compound in licorice, glycyrrhizin, blocks an enzyme that normally inactivates cortisol. The result mimics the effect of having too much of a hormone called aldosterone, which causes the body to retain sodium and lose potassium, driving blood pressure up.12Journal of Pharmacy Technology. Hypertension Secondary to Ingestion of Licorice Root Tea
This is not a theoretical concern. Case reports document patients developing clinically significant hypertension and dangerously low potassium from drinking several cups of licorice tea daily. In one published case, a patient who had been drinking up to six cups per day saw her hypertension and low potassium resolve completely within two weeks of stopping the tea.13PubMed Central. Hypertension induced by liquorice tea The occasional licorice lozenge during a sore throat is unlikely to cause problems, but daily consumption over the course of a multi-week illness adds up. If you have high blood pressure and find yourself gravitating toward licorice-flavored throat remedies, it is worth checking the ingredient list. Many herbal throat teas that do not advertise themselves as licorice tea still contain licorice root as an ingredient.
Putting It Together If You Manage Hypertension
For someone with normal blood pressure, a cold is unlikely to cause a clinically meaningful spike. Your readings might run a few points higher for a few days, and they will settle back once you recover. You probably would not notice at all unless you happened to check.
The picture is more nuanced for someone already being treated for high blood pressure. Each individual factor, the infection, the decongestant, the ibuprofen, the poor sleep, may contribute only a small increment. But these increments stack. A person taking pseudoephedrine for congestion, ibuprofen for a headache, and sleeping poorly for four nights is getting hit from multiple directions at once. None of those factors alone is likely to cause a dangerous spike, but together they can nudge readings into a range that feels uncomfortable or that moves a well-controlled patient temporarily out of their target zone.
The standard advice for people with hypertension is to favor acetaminophen over ibuprofen for pain relief during a cold, to use the lowest effective dose of any decongestant for the shortest possible time, and to check blood pressure at home if they have a monitor. Most pharmacies stock decongestant-free cold formulations specifically for this population. If readings climb notably despite these precautions, the illness itself is likely driving the change, and the priority shifts to recovering from the infection and sleeping as well as you can manage.
When Readings Stay Elevated After Recovery
One scenario that catches people off guard is when blood pressure remains elevated after the cold has cleared. If you were only checking your readings because you felt sick, and you discover numbers that seem higher than expected once you feel better, the cold may have simply prompted you to notice a pre-existing trend. Blood pressure drifts gradually over time, and many people go months between checks. It is worth repeating the measurements over a week or two once you are fully recovered, well rested, and off all cold medications. If the numbers remain high in that window, the cold was probably not the cause, it was the catalyst for paying attention.
Persistent post-infection hypertension that is genuinely new has been described after more severe viral infections. Research into SARS-CoV-2 in particular has documented lasting vascular effects in some patients, and there is older evidence linking other respiratory viruses to endothelial changes that can outlast the acute illness.2PubMed Central. Viral Endothelial Dysfunction: A Unifying Mechanism for COVID-19 For a typical rhinovirus cold, however, lasting blood pressure effects are not an established concern. If your readings do not normalize within a couple of weeks of being symptom-free, it warrants a conversation with your doctor about whether something else is going on, rather than attributing the change to a cold that has long since resolved.