A reading of 105/58 mmHg is technically in the “optimal” blood pressure category, which European guidelines define as below 120/80 mmHg. But the bottom number, 58, sits just under a threshold that gets attention in medical research: a diastolic pressure below 60. Whether that matters depends almost entirely on who you are, how you feel, and whether any underlying condition is pulling that number down. For a healthy, active adult with no symptoms, 105/58 is usually fine and even associated with lower cardiovascular risk. For an older adult or someone with heart disease, that diastolic reading warrants a closer look.
What the Two Numbers Tell You
Blood pressure is reported as two numbers. The top number, systolic pressure, reflects force on artery walls when the heart contracts. The bottom number, diastolic pressure, reflects force between beats, when the heart is resting and refilling. At 105/58, your systolic is well below the 120 mmHg line that separates “optimal” from “normal” in classification systems used by both American and European cardiology groups.1PubMed Central. New American and European Hypertension Guidelines, Reconciling the Differences That part of the reading is straightforwardly healthy.
The diastolic value of 58 is where things get more nuanced. There is no universally agreed-upon cutoff for “too low,” but researchers and clinicians tend to pay closer attention once diastolic pressure drops below 60 mmHg. A large study using U.S. national health data found that a diastolic reading below 60 in people who were not taking blood pressure medication was associated with a higher risk of death from all causes, but the same low reading in people whose diastolic dropped below 60 because of medication was not linked to increased risk.2PubMed Central. Association of low diastolic blood pressure with all‐cause death among US adults with normal systolic blood pressure That distinction is important: a naturally low diastolic may be a marker of underlying vascular changes, while a medication-induced low diastolic is not inherently dangerous.
When 105/58 Is Perfectly Normal
Plenty of people walk around with blood pressure in this range and are in excellent health. Younger adults, particularly women, tend to run lower on both numbers. Diastolic blood pressure generally rises until about age 45 and then starts to decline, largely because arteries gradually stiffen with age.3PubMed Central. Identification of Normal Blood Pressure in Different Age Group A 25-year-old with a diastolic of 58 is in a very different situation from a 75-year-old with the same reading.
Regular exercise is another common reason for low resting blood pressure. Training causes cardiovascular adaptations, including a lower resting heart rate and reduced arterial pressure, that are signs of a healthy, efficient system. Research confirms that regular physical activity is associated with lower blood pressure overall.4PubMed Central. Hypertension in athletes Follow-up studies of young athletes show that these adaptations, including cardiovascular changes, tend to reverse toward non-athlete levels once regular training stops.5PubMed. Resting electrocardiogram and blood pressure in young athletes and nonathletes: A 4-year follow-up So if you are physically active and feel well, a reading like 105/58 is more likely a reflection of fitness than a warning sign.
Symptoms That Suggest It Is Too Low
The key question is not “is the number low?” but “is the number causing problems?” Blood pressure that is technically low by population standards can still be perfectly adequate for your body. The line between healthy low pressure and problematic hypotension is drawn by symptoms, not a chart.
A population study published in the British Medical Journal found that low blood pressure is associated with persistent tiredness but that treatment is generally neither possible nor necessary. Interestingly, the researchers noted that low blood pressure may have opposite effects on mortality versus day-to-day quality of life: it protects against heart attacks and strokes but can leave people feeling drained.6British Medical Journal. Symptoms of low blood pressure: a population study Symptoms worth paying attention to include:
- Dizziness or lightheadedness: especially when standing up from a chair or getting out of bed.
- Fatigue: persistent tiredness that does not improve with adequate sleep.
- Blurred vision: brief episodes when changing position.
- Nausea: a vague sense of feeling unwell, particularly in the morning.
- Fainting: the most serious symptom, indicating your brain is not receiving enough blood flow in that moment.
If none of these apply to you, a reading of 105/58 is almost certainly not a clinical concern. If several of them sound familiar, it is worth investigating whether your blood pressure is part of the picture.
The Mood and Quality-of-Life Connection
One underappreciated aspect of chronically low blood pressure is its effect on how you feel emotionally. Research into affective states and low blood pressure has found that people with chronic hypotension report worse mood and a higher burden of depressive symptoms compared to people with normal pressure, even though low blood pressure is not considered a serious medical condition in itself.7PubMed. Affective impairment in chronic low blood pressure This does not mean low blood pressure causes depression in a straightforward sense, but the fatigue and mental fog that come with reduced perfusion can erode quality of life over time. If you have noticed both low readings and a persistent low mood or lack of motivation, the two may be related.
Why the Diastolic Number Gets Extra Scrutiny
The systolic number usually gets most of the medical attention when it comes to high blood pressure, but with low blood pressure the diastolic reading takes center stage. The heart muscle itself receives most of its blood supply during diastole, the relaxation phase between beats. If diastolic pressure is very low, coronary blood flow can theoretically be compromised.
This concern is at the heart of what researchers call the “J-curve” in blood pressure management. The idea is that while lowering blood pressure reduces cardiovascular events, pushing diastolic pressure too low may actually increase risk in people who already have coronary artery disease. Some guidelines have suggested maintaining diastolic pressure at a minimum of about 70 mmHg in patients with severe heart disease or thickened heart walls.8PubMed Central. The significance of the j-curve in hypertension and coronary artery diseases The J-curve effect appears to be specific to the heart: it has not been convincingly demonstrated for stroke or kidney disease, because the brain and kidneys are perfused mainly during systole rather than diastole.
The J-curve debate is far from settled, though. A commentary in JAMA Network Open pointed out that the relationship may be confounded: people whose diastolic pressure naturally drifts very low often have underlying conditions that independently raise their cardiovascular risk. The same analysis noted that intensive systolic blood pressure lowering, even in people who started with low diastolic readings, did not increase cardiovascular events. The reasoning is that lowering overall cardiac workload can compensate for the reduced diastolic perfusion pressure.9JAMA Network Open. Diastolic Blood Pressure and the J-Curve—Causal Effect or Confounding? Trial data from post-heart-attack patients found that low diastolic pressure was associated with higher risk, and that this relationship was sensitive to whether the patient had received reperfusion therapy, supporting the idea that actual coronary blood flow is involved, at least in people with blocked arteries.10PubMed. Myocardial reperfusion reverses the J-curve association of cardiovascular risk and diastolic blood pressure in patients with left ventricular dysfunction and heart failure after myocardial infarction
For someone without heart disease, these concerns are largely academic. A diastolic of 58 in a healthy person does not carry the same implications as a diastolic of 58 in someone who has had a heart attack or lives with heart failure.
Low Diastolic Pressure and Brain Health in Older Adults
Another area where low diastolic readings deserve attention is cognitive function, particularly in people over 65. A systematic review covering more than 200 prospective studies found that late-life low diastolic blood pressure, along with excessive blood pressure swings and drops upon standing, was associated with an increased risk of dementia.11PubMed. Blood Pressure and Risks of Cognitive Impairment and Dementia: A Systematic Review and Meta-Analysis of 209 Prospective Studies Earlier reviews reached similar conclusions, noting that both very high systolic and low diastolic values in later life may contribute to cognitive decline.12PubMed Central. Relation of Blood Pressure to Cognitive Impairment and Dementia
A Korean longitudinal study that tracked older adults over two years found that those with lower diastolic blood pressure performed worse on tests of memory recall and visuospatial ability compared to those with higher diastolic readings. The proposed mechanism involves reduced blood flow to the brain: when diastolic pressure stays low over time, the combination of arterial stiffness and atherosclerosis can lead to chronic underperfusion of brain tissue.13PubMed Central. Low Diastolic Blood Pressure and Cognitive Decline in Korean Elderly People Again, this is most relevant for older adults whose low diastolic pressure reflects aging-related vascular changes, not for younger people whose blood pressure is naturally on the lower end.
Postural Drops and Orthostatic Hypotension
If your blood pressure was measured at 105/58 while sitting, it could drop even further when you stand up. This transient drop is called orthostatic hypotension, and it is clinically defined as a decrease of at least 20 mmHg in systolic or 10 mmHg in diastolic pressure within a few minutes of standing. In clinical testing, roughly four out of ten patients being evaluated for blood pressure issues met criteria for orthostatic hypotension on a sit-to-stand test.14PubMed Central. Optimal Diagnostic Thresholds for Diagnosis of Orthostatic Hypotension with a “Sit-to-Stand Test” Those patients were referred precisely because of suspected blood pressure problems, so that percentage does not apply to the general population. But it illustrates how common postural drops are in people who already run low.
Your body relies on the autonomic nervous system to make rapid adjustments when you change position. The vagus nerve plays a central role in keeping blood pressure stable moment to moment. Research has shown that when vagal cardiac function is impaired, the body’s ability to buffer blood pressure against sudden changes weakens considerably.15PubMed. Vagal cardiac function and arterial blood pressure stability Dehydration, prolonged bed rest, heat, and alcohol can all impair these reflexes. If you have a baseline of 105/58 and experience dizziness every time you stand, the culprit may be an exaggerated postural drop rather than your resting number being dangerous on its own. Simple countermeasures like standing up slowly, staying hydrated, and increasing salt intake (if your doctor agrees) can help.
Nutritional Causes Worth Checking
Most cases of naturally low blood pressure do not have a dramatic underlying cause, but a few nutritional deficiencies can push blood pressure lower than it should be. Vitamin B12 deficiency is one that shows up in the medical literature more than people might expect. Case reports have documented hypotension severe enough to require emergency treatment in a previously healthy young man with B12 deficiency, with full recovery after supplementation.16PubMed Central. Hypotension: an unusual presentation of vitamin B12 deficiency, with complete recovery following cyanocobalamin therapy In older adults, B12 deficiency has been linked to orthostatic hypotension that resolved with replacement therapy.17PubMed Central. Orthostatic hypotension as a manifestation of vitamin B12 deficiency
These are case reports, not large population studies, so B12 deficiency is not a common explanation for low blood pressure across the board. But if your blood pressure is lower than expected and you also have symptoms like tingling in your hands or feet, fatigue, or difficulty concentrating, checking B12 levels (along with iron and folate) is a reasonable step. Vegans and vegetarians, older adults with reduced stomach acid, and people taking certain medications are at higher risk for B12 deficiency.
Getting an Accurate Reading
Before worrying about a reading of 105/58, it is worth making sure the number is accurate. Blood pressure measurement is surprisingly sensitive to technique. Cuff size is one of the biggest sources of error: using a cuff that is too large for your arm will produce artificially low readings, while a cuff that is too small inflates the numbers. Research in schoolchildren demonstrated that “normal blood pressure” curves changed substantially depending on which cuff was used, with the wrong cuff introducing systematic bias.18PubMed. Influence of cuff size on blood pressure among schoolchildren The same principle applies to adults: if you have a slender arm and use a standard cuff, or a large arm and use a small cuff, the reading may not reflect your actual pressure.
Other common sources of error include talking during measurement, sitting with crossed legs or an unsupported back, measuring immediately after exercise or caffeine, and using a wrist monitor without keeping the wrist at heart level. A single reading is also just a snapshot. Blood pressure fluctuates throughout the day, dropping at night and rising in the morning. Researchers have been exploring wearable sensors that track blood pressure continuously using light-based sensors on the wrist, and early results suggest these devices can estimate trends and overnight dips.19Physiological Measurement. Estimating blood pressure trends and the nocturnal dip from photoplethysmography These tools are not clinically validated for diagnosis yet, but they hint at a future where a single snapshot reading matters less because continuous data will give a much richer picture.
If you are concerned about a reading of 105/58, the most useful step is to take multiple readings over several days, at different times, using proper technique. If the pattern holds and you feel fine, you are likely looking at your natural baseline. If the pattern holds and you have symptoms, bring those readings to your doctor as a starting point for investigation.
When a Low Reading Deserves Medical Attention
Most of the serious implications of low blood pressure discussed in this article apply to specific groups: older adults with stiffening arteries, people with existing heart disease, patients on multiple medications. For those populations, a diastolic below 60 may be a signal that the cardiovascular system is under strain. The U.S. national health data study mentioned earlier found that the association between low diastolic pressure and death was driven by factors like heart failure, prior heart attack, diabetes, and advanced age, all of which can independently lower diastolic pressure as the disease progresses.2PubMed Central. Association of low diastolic blood pressure with all‐cause death among US adults with normal systolic blood pressure In those cases, low diastolic pressure is less a cause of trouble and more a marker of it.
Situations that warrant prompt medical evaluation include a sudden drop from your usual blood pressure (not just a low stable baseline), fainting or near-fainting episodes, blood pressure that drops steeply when you stand up, and low pressure accompanied by a rapid heart rate, confusion, or cold or clammy skin. These could indicate dehydration, blood loss, infection, an allergic reaction, or an endocrine problem. A reading of 105/58 taken casually at home, in the absence of symptoms like these, is not an emergency by any standard guideline.