I've read recently that magnetic storms cause: "heart failure, heart attack, strokes and insomnia". This comes from major newspaper in Lithuania (EU country), here is the link to the article (in Lithuanian). The evidence presented is increase in patients in hospitals. Naturally I'm skeptic about these claims, because this is the first time it became an issue and the solar flares and geomagnetic storms happen all the time. I've googled around, but did not find anything credible looking. So is there any scientific evidence, or collected data which either proves or disproves the hypothesis in the title?

  • There is a related question, but it addresses a different issue.
    – mpiktas
    Commented Mar 9, 2012 at 7:57
  • Solar storms have taken down the power grid in Quebec in the past, so they can definetly affect electronics (It's basically an EMP). If I had a pacemaker and there was a big solar storm inbound I would be worried. As for affecting normal healthy people, I would be surprised EMP's aren't generally known as people killers directly (of course destroying the circuits in that aircraft they are in causes death indirectly, but the EMP itself isn't what killed them, it was the sudden stop when they hit the ground).
    – Ardesco
    Commented Mar 12, 2012 at 22:38
  • 1
    This study in a peer-reviewed journal contains an overview of scientific literature on the topic: rspb.royalsocietypublishing.org/content/early/2012/03/12/…
    – Slaviks
    Commented Mar 17, 2015 at 19:45
  • 1
    @Slaviks: Your bounty message claims you lack the reputation points to post an answer. You only need 10 - you still have that, even after the bounty. Go ahead and post an answer!
    – Oddthinking
    Commented Mar 17, 2015 at 23:06
  • 1
    @Slaviks If you have a chance, there's a bounty waiting. . . If you can get 10 rep somewhere else, you can give it a shot. Oh, and clarification: " I'm still not satisfied" [with the attention this question has received].
    – HDE 226868
    Commented Mar 29, 2015 at 14:21

2 Answers 2


Yes, geomagnetic activity affects health.

Yes, geomagnetic activity has been found to cause strokes:

Geomagnetic storms can trigger stroke: evidence from 6 large population-based studies in Europe and Australasia Stroke 2014 Jun; 45(6):1639-45 reports a 11,453 person study spanning 1981-2004.

exposure to geomagnetic storms (with Ap Index >60) on an individual level increases the relative risk of stroke by 19% across all ages (95% CI, 11%–27%) and by 37% (95% CI, 21%–54%) across those aged <65 years


Timing of life-threatening arrhythmias detected by implantable cardioverter-defibrillators in relation to changes in cosmophysical factors Cardiology Journal 2008, Vol. 15, No. 5, pp. 437–440 finds that geomagnetic activity provides a health benefit and hypothesizes that :

higher CRA [cosmic ray acitivity], which occurs at times of lower GMA [geomagnetic activity] and lower solar activity [20], contributes to electrical heart instability, especially in patients with damaged heart muscles as a consequence of repeated AMI or ischemic cardiomyopathy, as in our series.

In other words, because the Earth's surface is more protected form cosmic rays during times of increased geomagnetic activity, problems caused by comsic rays are reduced during high geomagnetic activity.

and the review article Cardiac Arrhythmia and Geomagnetic Activity Indian Pacing Electrophysiol J. 2006 Jan-Mar; 6(1): 49–53 similarly finds:

there is an inverse relationship between the frequency of cardiac arrhythmic events and SCD [Sudden Cardiac Death] and the level of daily GMA [Geomagnetic Activity]

and concludes:

According to the various studies, we can presume that the GMA has some protective effect on cardiac arrhythmias and SCD

So overall, yes geomagnetic activity affects health, but there can be beneficial affects and negative affects.

  • 1
    Dave, you're everywhere! Nice answer.
    – HDE 226868
    Commented Mar 30, 2015 at 20:10

I'll get this out there before I go on: people in aircraft (and spacecraft) are susceptible to harmful radiation from solar activity, because Earth's atmosphere does not provide significant shielding at the altitudes that most airplanes fly at. According to NASA, radiation levels an airplane traveling at the height that most passenger planes fly at are about ten times as great as those on the ground. Solar activity can multiply that amount by another ten, making aircraft pretty bad places to be during a solar storm - if you get unlucky.

Studies on cosmonauts on Soyuz and Mir supposedly show that geomagnetic storms cause

a change of pulse and blood pressure, vegetative disorders, reduction of heartbeat rate variability and the power of respiratory undulations, and in a more irregular heartbeat pattern. Reactions varied depending on the duration of the flights and an ability of cosmonauts to adapt themselves to the new environment."

The study is downloadable via pdf here. Quoting directly from the conclusion,

In this paper it is shown for the first time that geomagnetic disturbances have a specific influence on autonomic regulation of blood circulation in cosmonauts during the flight dependently of duration of weightlessness conditions. Magnetic storms change the regulation of the vascular tonus and affect the autonomic balance both during their direct action and during the post time in the nearest 24 hours.

. . .

At the initial stage of a long space flight (on the 2nd day and at the end of the 1st month flight), the effect of magnetic storms reconstructs the mechanism of regulation of the vascular tonus and changes the activity of the subcortical cardio-vascular center. This results in the development of a general non-specific stress reaction, which is characterized by enhanced tonus of the sympathetic nervous system (increased heart rate, reduced spectrum power of respiratory waves, etc.) and by involvement of the higher levels of physiological control in regulation processes. The reconstruction of regulation processes may be followed by increase of instability of the sinus node of accompanied by increased occurrence of the heart rhythm arrhythmias.

At the end of six-month flight, the magnetic storm may cause an activation of the parasympathetic regulation as a result of destabilization of the previously established autonomic homeostasis. In this period, the autonomic regulation system is under functional strain due to long duration flight in weightlessness. Any additional stress associated with the magnetic storm is likely to lead to a short-term over-strain of the regulation mechanisms. Thus, the reaction to the magnetic storm depends on the initial functional background, in particular on the state of the autonomic regulation mechanisms.

The group of cosmonauts who landed on the day of a magnetic storm displayed variations in the tonus of vascular regulation 4 - 8 hours after landing, consisting of increased heart rate against the background of deviations in the mechanism of autonomic regulation. It implies the deceleration of re-adaptation processes, which is of great practical importance for planning the recovery procedures after a long space flight.

Most people, however, are not in Earth orbit, and so are not affected by the same levels of radiation that the cosmonauts were.

Babayev, Solar and Geomagnetic Activities and Related Effects on the Human physiological and Cardio-Health State: Some Results of Azerbaijani and Collaborative Studies

An analysis of four separate studies was carried out by a member of the Azerbaijani National Academy of Sciences. The study analyzed prior papers, which partly used "electroencephalographic (EEG) investigations", and found that

It is experimentally established that in middle latitudes weak and moderate geomagnetic storms do not cause significant changes in the human brain bio-electrical activity and exert only stimulating influence meanwhile severe disturbances of geomagnetic field (storms) cause negative influence, significantly disintegrate functionality of brain, activate braking processes and amplify the negative emotional background of an individual.

It was found that

Changes in geomagnetic conditions mostly affect the activity of regulating systems, which are related to high cortical mechanisms of regulation and sub-cortical integrative apparatuses responsible for organization of routine activity of an organism, and for adaptation to changes of a physical environment (Babayev & Allahverdiyeva 2005).

Interestingly enough, another conclusion was that

There is high correlation between cosmic ray activity (CRA) (neutron data on the surface of Earth) and number of traffic accidents.

Another experiment was mentioned in the study.

The experiment was based on a method of electrical conductivity measurements of biologically active (acupunctural) points of human skin. The method (electroacupunctural method by Dr. R.Voll) is very sensitive to current state of an organism and characterizes the functional condition of different organs and systems and enables expressing so-called Health Status of Group in the units, suitable for comparison with meteorological and physical parameters. Measurements were carried out daily with permanent group of functionally healthy persons (Moscow - 19, Yakutsk - 22, Baku - 12 volunteers). Daily monitoring of nervous, endocrine, lymphatic systems; blood, lungs, thick and thin intestine, heart and parenhimatic organs, allergy and hypophisis was conducted simultaneously with analyses of space weather (parameters of SA and GMA), as well as local meteorological parameters (temperature, atmospheric pressure, humidity, wind speed, etc.). It was found that: (i) human reaction to sharp changes of external parameters evolves like typical stress-reaction with hyperfunction and depression phases; (ii) the lower the latitude, the more the human body becomes susceptible to changes of meteorological parameters (especially humidity and temperature), the less sensitive it is to changes of GMA.

More results from a different study were mentioned:

The conclusion is that both SCD (sudden cardiac death) mortality and AMI (acute myocardial infarction) occurrence increase in high CRA (cosmic ray activity) (neutron) levels, and GMA (geomagnetic activity) and CRA could be considered as two of the most significant regulating factors in human homeostasis. Not only high levels, but also low levels of GMA influence the number of considered acute cardiac events (Stoupel et al. 2008).

A final study was analyzed:

Results revealed statistically significant increments for the mean systolic and diastolic blood pressure values of the group with geomagnetic activity increase. ABP (arterial blood pressure) values started increasing two days prior to geomagnetic storms and kept their high values up to two days after the storms.

The Azerbaijani paper's conclusions were simple:

Weak and severe geomagnetic storms affect the functional state (bioelectrical activity) of the human brain in a different way.

Geomagnetic storms amplify the negative emotional background of an individual and can affect, for example, the brain of a driving person, thus increasing the risk of an accident.

Parameters reflecting a state of vegetative sphere of a human being significantly differ and are dependent on the strength of geomagnetic disturbances.

Heart rate dynamics (variations) of a human can be affected by space weather changes like variations in geomagnetic activity and cosmic ray intensity.

Different types of geomagnetic storms (i.e., magnetic-cloud origin or caused by high- speed solar wind streams) affect cardio-vascular system in different ways.

Russian Academy of Sciences

A Russian study also found that heart problems increased around the time of geomagnetic storms:

Medical statistics for Moscow show that 70% of all micro variations, caused by geomagnetic disturbances, are accompanied by an abnormally high incidence of heart attacks (a growth of about 13%), and blood-strokes (7.5% growth). The low and extremely low frequency electromagnetic fields destabilize the heartbeat, leading to a sudden death or infarction. Medical experts have finally explained why heart attacks take a heavy toll before a magnetic storm - because micro variations begin 24 hours before the storm.

This can be found at PubMed, but, alas, the full text is not accessible.

Possible mechanisms

I'm still not convinced, because there has to be an explanation for such a claim. It's all well and good to claim a cause-and-effect, but in this case, a proposed mechanism would be really nice.

Fortunately, there are some.

  • Cryptochromes. Slaviks mentioned this, and I would love to see an answer based on that resource, which is astoundingly excellent. I'll stick to the explanation I found, which is that the chemical is related to our ability to sense magnetic fields, and geomagnetic storms mess with it, messing with our circadian rhythms.


    [David] Close instead argues that the vestigial human cryptochrome compass system alters stress response in the hypothalamic–pituitary–adrenal (HPA) axis, which regulates much of the body's activities.

  • Pineal Gland. I have not been able to confirm whether the biochemical reactions involve cryptochrome, but I did learn that, apparently, geomagnetic activity affects the pineal gland in the brain:

    Today’s monster geomagnetic storm, and the explosion of solar flares and coronal mass ejections over the past week, have been wreaking havoc on people’s moods, sleeping patterns, and a host of other human health effects. Many people are experiencing disturbances and disturbances with their circadian rhythms, waking up around 2am and having trouble getting back to sleep. “Solar storms desynchronize our circadian rhythm (biological clock). The pineal gland in our brain is affected by the electromagnetic activity, and [solar storms cause] the gland to produce excess melatonin, the brain’s built in ‘downer’ that helps us sleep. ‘The circadian regulatory system depends on repeated environmental cues to [synchronize] internal clocks,’ says psychiatrist Kelly Posner, Columbia University. ‘Magnetic fields may be one of these environmental cues.’ ”

    It is expanded upon here.


I'm convinced that there might be interference with circadian rhythms, and there can certainly be drastic effects on people in airplanes and spacecraft, but there is not a wide range of definitive evidence that there are other effects as drastic as claimed.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .