COVID and Low Blood Pressure: What You Need to Know

COVID-19 can cause low blood pressure through several distinct pathways, both during active infection and for months or even years afterward. During a severe acute infection, the virus can trigger a dangerous drop in blood pressure through overwhelming inflammation, direct heart damage, and disruption of the hormonal system that regulates blood vessel tone. In the longer term, a substantial fraction of people recovering from COVID develop autonomic nervous system problems that make their blood pressure unstable, particularly when standing. These are not rare curiosities: one review estimates autonomic dysfunction could affect roughly a third of highly symptomatic COVID patients.

How Acute COVID Infection Drives Blood Pressure Down

When COVID-19 becomes severe enough to land someone in an ICU, dangerously low blood pressure is one of the most common life-threatening complications. The medical term for this is vasoplegic shock, a state where blood vessels relax so profoundly that the heart cannot maintain adequate pressure to supply the organs, no matter how hard it pumps. In children and adolescents with multisystem inflammatory syndrome (MIS-C), a post-COVID complication, vasoplegic shock has been identified as the dominant pattern of circulatory failure. Researchers studying these young patients found they had very high cardiac output paired with very low vascular resistance in the first 24 hours, meaning the heart was working overtime but the blood vessels had essentially lost their grip.¹

The underlying driver of this collapse is the massive inflammatory response that severe COVID provokes. A flood of inflammatory signaling molecules, sometimes called a cytokine storm, causes blood vessels to dilate uncontrollably. One mechanism involves the release of nitric oxide in response to inflammation, which forces vessels to widen.² At the same time, the virus damages the endothelial cells that line the inside of blood vessels, causing swelling, micro-clots, and constriction at the capillary level. The result is a paradox: large vessels are too relaxed while the smallest vessels are clogged and damaged, creating a chaotic situation where blood pressure plummets even as tissues are starved of oxygen.

The Renin-Angiotensin System and ACE2

SARS-CoV-2 enters human cells by latching onto a protein called ACE2, which normally plays a key role in regulating blood pressure. ACE2 helps produce a molecule that relaxes blood vessels and keeps inflammation in check. When the virus binds to ACE2 and drags it inside the cell, the amount of functional ACE2 on the cell surface drops. This disrupts the balance of the renin-angiotensin system, the body’s main hormonal circuit for controlling blood pressure.³

Research measuring the actual hormone levels in COVID patients has confirmed this disruption. In severe cases, levels of angiotensin I and angiotensin II were substantially higher than in milder cases, with critically ill patients on ventilators showing the most extreme elevations.⁴ That might seem counterintuitive because angiotensin II is a potent vasoconstrictor that would normally raise blood pressure. But in the setting of severe COVID, the system is in disarray: the counterbalancing arm that ACE2 normally supports is suppressed, vascular inflammation is rampant, and the downstream effects of prolonged vasoconstriction actually worsen endothelial damage and contribute to cardiovascular injury.⁵ In other words, the machinery meant to stabilize blood pressure gets overwhelmed from both directions.

Direct Heart Damage

Beyond vascular effects, COVID can also lower blood pressure by weakening the heart itself. Myocarditis, or inflammation of the heart muscle, is a recognized complication. When the heart muscle is inflamed, it cannot pump as effectively. In one documented case of COVID-related multisystem inflammatory syndrome, cardiac imaging showed a left ventricular ejection fraction of 45% (below the normal range) along with low cardiac output and areas of the heart wall that had stopped contracting.⁶ A weakened pump naturally means lower pressure in the system. Though frank myocarditis is not the most common COVID complication, subtler forms of cardiac stress can compound the blood pressure problems created by vascular and inflammatory mechanisms.

Adrenal Insufficiency as a Hidden Cause

There is another, less obvious pathway by which COVID can cause low blood pressure: disruption of the adrenal glands. The adrenal glands produce cortisol and aldosterone, hormones critical for maintaining blood pressure. Researchers have documented cases where COVID appears to unmask or trigger adrenal insufficiency, a condition in which these glands fail to produce enough hormones. One case report described a patient presenting after COVID with dehydration, hypotension, and skin darkening, classic signs of adrenal failure. Testing confirmed very low cortisol, high ACTH (the brain’s signal demanding more cortisol), and autoantibodies attacking the adrenal gland.⁷

The connection between COVID and the adrenal axis is not fully mapped, but the virus’s known interaction with ACE2 receptors found in adrenal tissue, combined with the intense immune activation it provokes, may damage or trigger autoimmune responses against the glands. This matters practically because adrenal insufficiency is treatable with hormone replacement, but it has to be recognized first. If you develop persistent fatigue, dizziness, unexplained weight loss, salt cravings, and low blood pressure after COVID, this diagnosis is worth considering with your doctor.

Autonomic Dysfunction and Orthostatic Hypotension in Long COVID

The most widely recognized link between COVID and ongoing low blood pressure problems is autonomic dysfunction, particularly the kind that causes trouble when you stand up. The autonomic nervous system handles the unconscious adjustments your body makes to keep blood pressure stable: when you stand, it quickly tightens blood vessels in the legs and speeds up the heart to prevent blood from pooling below the waist. When this system malfunctions, blood pressure drops upon standing, a condition called orthostatic hypotension, or the heart rate spikes excessively to compensate, known as postural orthostatic tachycardia syndrome (POTS).

Both conditions are now firmly established as components of long COVID. A major review in Nature Reviews Cardiology described cardiovascular autonomic dysfunction as an important part of post-COVID syndrome, noting that it can manifest as disorders associated with low blood pressure, including orthostatic hypotension, drops in blood pressure after meals, and recurrent fainting.⁸ One study found that at the time of hospital discharge, nearly half of COVID patients showed orthostatic hypotension on testing, while about one in six met criteria for POTS.⁹

A multicenter study of long COVID clinic patients found that more than half experienced symptoms of orthostatic intolerance during a formal tilt test, and more than one in ten met clinical criteria for either POTS or orthostatic hypotension. Strikingly, nearly half of those with abnormal results had never reported typical symptoms of feeling faint upon standing before the test, suggesting this problem is easy to miss if no one looks for it.¹⁰ In patients with post-COVID POTS specifically, researchers found more daytime episodes of abnormally low blood pressure compared to controls.¹¹

Why the Autonomic Nervous System Goes Wrong After COVID

Researchers have proposed several mechanisms for how SARS-CoV-2 damages autonomic function. One possibility is that the virus directly invades brain regions that control the autonomic nervous system, such as the hypothalamus and the medulla, either by traveling along nerves or through the bloodstream. However, the current evidence leans more toward indirect damage, with most neurological complications appearing to stem from the immune response rather than the virus camping out in the brain.¹²

One of the more compelling lines of evidence involves autoantibodies, immune proteins that mistakenly attack the body’s own tissues. In a case of severe orthostatic hypotension following COVID, researchers screened the patient’s blood and found eight different autoantibodies targeting the autonomic nervous system and the blood pressure-regulating hormone system. Treatment with intravenous immunoglobulin (a therapy that damps down the immune attack) led to significant improvement.¹³

Broader studies have extended this finding. In one analysis, about two-thirds of post-COVID patients had autoantibodies targeting a family of cell-surface receptors involved in vascular regulation, compared to only about a fifth of people who had recovered from COVID without ongoing symptoms. Several of these autoantibodies showed a strong negative correlation with blood pressure, meaning higher autoantibody levels tracked with lower blood pressure readings.¹⁴ This suggests that in at least some patients, the immune system’s response to the virus is actively sabotaging the body’s ability to maintain normal blood pressure.

What It Feels Like and How It Affects Daily Life

The clinical presentation of post-COVID autonomic dysfunction goes well beyond simply feeling lightheaded. Patients commonly report dizziness, racing heart, excessive sweating, headaches, fainting spells, unstable blood pressure, inability to tolerate exercise, and cognitive problems often described as “brain fog.”¹⁵ Many of these symptoms worsen with standing, heat, meals, or exertion, all situations that challenge the cardiovascular system to redirect blood flow.

The cognitive effects are particularly disabling and probably underappreciated as a blood pressure issue. Research using reaction-time testing showed that when long COVID patients were tilted upright (simulating standing), their cognitive performance dropped, while healthy controls actually got slightly faster. The difference was statistically significant for multiple types of reaction time testing, and it persisted for days afterward.¹⁶ In plain terms, standing up makes it harder for these patients to think clearly, and the fog does not lift quickly once they sit back down. For anyone trying to work at a desk or stand in a meeting, this has obvious consequences.

Blood Pressure Medications and COVID

Early in the pandemic, a significant scare circulated about whether common blood pressure medications, specifically ACE inhibitors and angiotensin receptor blockers (ARBs), might make COVID worse. The logic seemed plausible on the surface: since the virus uses ACE2 to enter cells, and these drugs interact with the renin-angiotensin system, might they increase vulnerability? This concern led some patients to stop their medications, which was a dangerous move.

Major medical societies investigated the question and landed firmly on the side of continuing treatment. The British and Irish Hypertension Society, along with international partner organizations, issued statements advising against stopping these medications, warning that the unintended consequences of uncontrolled blood pressure posed a greater danger than any theoretical COVID risk.¹⁷ Clinical data from Wuhan supported this position, showing that ARB drugs did not cause worse COVID outcomes in hypertensive patients and may have even been associated with a lower risk of heart failure.¹⁸ A separate analysis concluded that withdrawing these medications would have uncertain benefits but definite downsides, including uncontrolled blood pressure, deteriorating heart and kidney function, and potentially more complications than the infection itself.¹⁹

If you are on blood pressure medications and you get COVID, the clear consensus is to keep taking them unless your doctor specifically tells you otherwise after evaluating your individual situation. If COVID makes you severely ill with vomiting, diarrhea, or reduced fluid intake, your doctor might temporarily adjust doses because dehydration combined with blood pressure drugs can cause excessively low readings. But that is routine sick-day management, not a COVID-specific reason to abandon the medication.

How Doctors Test for Post-COVID Blood Pressure Problems

If you suspect your blood pressure problems are linked to COVID, a tilt-table test is considered the gold standard for evaluation. During this test, you lie flat on a special table for several minutes while baseline heart rate and blood pressure are recorded, then the table is tilted to 70 degrees (nearly upright) for 30 minutes while continuous measurements are taken. The idea is to stress the autonomic system in a controlled way and see how blood pressure and heart rate respond. A drop in systolic blood pressure of 20 mmHg or more, or a heart rate rise of 30 beats per minute or more without a corresponding blood pressure drop, can help pin down whether you have orthostatic hypotension or POTS.²⁰

A simpler version you can do at home, called an active standing test, involves lying down for five minutes, recording your blood pressure, then standing up and checking it again at one and three minutes. This is not as precise as a tilt table, but significant drops or dramatic heart rate increases can be enough to prompt a referral. Keep in mind that many people with post-COVID orthostatic problems did not recognize the pattern in their own symptoms until formal testing revealed it, so do not assume you would know.

Similarities with Other Post-Viral Conditions

The autonomic dysfunction seen after COVID is not unique to SARS-CoV-2. Researchers have noted striking overlap with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a condition that has long been recognized as a post-viral complication of other infections. A study directly comparing the two groups found extensive similarities: reduced blood flow to the brain upon standing occurred in over 90% of both long COVID and ME/CFS patients, and mild-to-moderate widespread autonomic failure was present in the vast majority of both groups. Rates of POTS and orthostatic hypotension were almost identical between the two conditions.²¹

A separate study comparing the two conditions confirmed high rates of POTS in both, with ME/CFS patients showing somewhat higher rates than post-COVID patients in that particular cohort.²² This overlap is both frustrating and encouraging. Frustrating, because it suggests the underlying mechanism may be a common vulnerability of the autonomic nervous system to immune disruption, meaning it could happen after many different infections. Encouraging, because it means the decades of clinical experience managing dysautonomia in ME/CFS can be directly applied to long COVID patients.

Children and Multisystem Inflammatory Syndrome

Children were generally less likely to become severely ill with acute COVID, but a subset developed multisystem inflammatory syndrome in children (MIS-C), a delayed inflammatory reaction that typically appeared weeks after the initial infection. Among the cardiovascular symptoms documented in MIS-C cohorts, low blood pressure appeared alongside chest pain, fainting, and myocarditis.²³ As noted earlier, the hemodynamic profile in these children was dominated by vasoplegic shock, where the blood vessels lost tone while the heart tried to compensate by pumping harder and faster.

Most children with MIS-C recovered cardiovascular function within days to weeks with appropriate treatment, including intravenous immunoglobulin and sometimes vasopressor medications. However, long-term follow-up data remain limited, and some clinicians have reported persistent autonomic complaints in a fraction of children after MIS-C. Parents whose children had MIS-C should be aware that new-onset dizziness, exercise intolerance, or fainting months later could be related.

Can COVID Vaccination Cause Similar Problems

POTS and related autonomic conditions have been reported not only after SARS-CoV-2 infection but also, less commonly, after COVID vaccination. A review in Nature Reviews Cardiology noted that POTS, mast cell disorders, chronic fatigue, and general dysautonomia are diagnosed more often in the three months following infection but can also develop after vaccination.²⁴ The rates after vaccination appear to be substantially lower than after infection itself, but the association exists and deserves acknowledgment rather than dismissal. The mechanism likely involves the immune response to the spike protein, whether encountered through the virus or through the vaccine, though infection brings a much larger and more prolonged immune challenge along with direct tissue damage that the vaccine does not cause.

Practical Management Strategies

If you are dealing with low blood pressure or orthostatic symptoms after COVID, there are concrete steps that can help while you work with a healthcare provider on a longer-term plan:

• Increase fluid and salt: Boosting blood volume is the simplest first intervention. Many dysautonomia specialists recommend two to three liters of water daily and additional dietary salt, sometimes in the form of electrolyte drinks or salt tablets, unless you have a condition like heart failure or kidney disease that limits salt intake.
• Compression garments: Waist-high compression stockings or abdominal binders can reduce blood pooling in the legs and abdomen when standing.
• Positional awareness: Rise from lying or sitting slowly. Crossing your legs, tensing your thigh muscles, or squatting can serve as emergency counter-maneuvers if you feel faint.
• Graded exercise: Reclined exercise such as rowing, recumbent cycling, or swimming puts less orthostatic stress on the body than upright activities and can gradually recondition the cardiovascular system. Pushing too hard too soon often causes setbacks.
• Medication options: Depending on the specific pattern (primarily low blood pressure versus primarily rapid heart rate), doctors may prescribe fludrocortisone to boost blood volume, midodrine to tighten blood vessels, or beta blockers to slow heart rate. These require medical supervision and dose adjustment.

The management approaches above are drawn from decades of experience treating dysautonomia from various causes and have been recommended in the context of long COVID specifically.²⁵ Recovery timelines vary widely: some people improve within months, while others deal with symptoms for a year or more. The autoantibody findings suggest that for some patients, more targeted immune therapies may eventually become available, but this remains an active area of research rather than standard practice.

When Low Blood Pressure After COVID Needs Urgent Attention

Most post-COVID blood pressure issues, while aggravating and sometimes disabling, are not immediately dangerous. But certain situations call for prompt medical evaluation. If your systolic blood pressure consistently reads below 90 mmHg, if you are fainting rather than just feeling dizzy, if you develop new chest pain or shortness of breath alongside low readings, or if you notice dark-colored urine and severely reduced urination suggesting dehydration, these warrant same-day or emergency evaluation. Low blood pressure during active COVID illness should always be taken seriously, as it can signal the progression toward shock, myocarditis, or organ damage that requires hospital-level interventions.

For the longer-term scenario, the biggest risk is not the low readings themselves but the secondary consequences: falls and injuries from fainting, inability to exercise or work, and the cascading effects of prolonged inactivity on mood, muscle, and cardiovascular fitness. Getting an accurate diagnosis early, ideally with formal autonomic testing, puts you in a better position to pursue treatments that actually match your underlying problem rather than guessing.