Can Your Emotions Change Your Blood?
A curious experiment, a drop of blood, and a much bigger question about how deeply our emotional state reaches into the body
A little while ago, I came across a video that made me stop scrolling. It showed fresh blood under a dark-field microscope while the woman whose blood was being observed deliberately moved herself through very different emotional states: sadness, love, fear and, eventually, a deeply spiritual experience. Fresh samples were taken along the way and, according to the people watching them, not only did the samples look different, but the cells appeared to behave differently too.
Naturally, that was enough to send me down the rabbit hole. You cannot show me something like that and expect me to go calmly back to work, recipes or whatever else I was supposed to be doing. 😁 I wanted to know where the footage came from, who the woman was, what they actually did and, most importantly, whether there was a genuinely interesting question hiding underneath those rather dramatic microscope images.
The woman was Rebecca Marina, an EFT practitioner. She carried out the experiment with Patricia Felici, who took fresh finger-prick samples while Rebecca deliberately created different emotional states. Rebecca later published her own account of what they had done, and psychologist and EFT practitioner Dr Patricia Carrington watched a 34-minute documentary showing the experiment. Carrington described seeing apparent differences in the movement, shape and background of the blood cells as Rebecca's emotional state changed. She was also very clear that this was not a controlled experiment, and that dark-field microscopy used in this way had not been scientifically validated as a method of identifying emotional states.
For me, those two facts can comfortably exist together. Something can be interesting without already being proven. We can look at what was observed, distinguish it from how it was interpreted and then ask whether the question deserves another look. In this case that question is wonderfully simple: when our emotional state changes, how far through the body does that change travel?
It wasn't even supposed to be an experiment with blood
Rebecca's original idea had been inspired by Masaru Emoto's work with frozen water crystals. According to her own account, she and Patricia attempted to look at water crystals under the dark-field microscope, only to discover that the heat from the microscope light melted them before they could properly examine them. So the original plan rather literally dissolved in front of them.
Sometimes an experiment begins with a university grant, a research team and three years of careful planning. Sometimes the ice melts and you move on to Plan B. 😂
Rebecca and Patricia had already experimented with viewing her fresh blood, so they decided to use that instead. Their plan was straightforward: Rebecca would deliberately enter one emotional state very strongly, Patricia would take a blood sample immediately afterwards, and they would look at it on the monitor attached to the microscope. One particularly interesting element was Rebecca's use of EFT — Emotional Freedom Techniques. She wasn't using tapping only to calm herself down. She deliberately used it to strengthen her contact with an emotion before the sample was taken, describing an intention to let each emotional state become very powerful within her.
Even before they reached the planned sequence of emotions, however, something caught their attention.
Before and after EFT
Rebecca's first sample showed many red cells clustered together. In her own account, she attributed this to foods she had eaten earlier and to her ideas about lectins and blood type. I wouldn't present that explanation as established haematology, and fortunately we don't need it for the interesting part of the story.
Rebecca used EFT and another sample was taken. In the second image, the red cells appeared considerably less clustered and more separate. Carrington later described seeing this same sequence in the documentary: red cells appearing clumped together before EFT and, afterwards, appearing to drift independently through the plasma. She did not claim to know the mechanism and openly acknowledged that she was not an expert in interpreting dark-field microscopy, but she thought the visual difference was striking enough to make her wonder whether this might be worth studying properly.
[IMAGE — BEFORE / AFTER EFT]
Original dark-field images from Rebecca Marina's exploratory experiment. Source: EFT Universe.
Of course, two different drops of fresh blood are not automatically comparable laboratory specimens. The appearance of a sample can be affected by the way it is prepared, by pressure beneath the coverslip, temperature, timing and other variables. So these pictures do not allow us to conclude that EFT “unclumps red blood cells”. What they do explain is why the people in the room became curious enough to continue.
And that was only the beginning.
Sadness
Rebecca's first deliberately induced state was sadness. She used EFT while thinking about things that genuinely upset her and, according to her account, entered the feeling deeply enough that she was crying when Patricia took the blood sample. She didn't wait for the emotion to fade first; the sample was taken while she was still in it.
What surprised them was the movement. Rebecca described the cells as moving very rapidly rather than sluggishly, and she believed considerably more white blood cells were visible than in the earlier sample. She also noticed that many of the red cells appeared elongated and described them as having a “teardrop” formation. Importantly, Rebecca herself did not pretend to know why this had happened. In her account she explicitly wondered whether there might be a scientific explanation and said that she simply knew what she had seen on the screen.
[IMAGE — SADNESS]
Original sample labelled “Sadness” by Rebecca Marina.
There is an obvious temptation here to make the story wonderfully poetic: Rebecca cries and her red cells turn into little tears. Biology apparently decided subtlety was overrated that afternoon. 😂 But the photograph cannot tell us why those cells looked that way. Shape changes can have many explanations, including ordinary variation and sample preparation. To establish that sadness itself produces a repeatable morphological pattern, we would need many participants, standardised sampling and analysis by people who did not know which emotional condition they were looking at.
Still, imagine being in that room. Rebecca is visibly emotional, another sample goes under the microscope and it seems to look and move differently from the previous one. I can understand perfectly well why nobody said, “Oh well, never mind,” and went home.
Love
Rebecca next moved herself deliberately into what she described as the energy of love. Again, she used EFT to create the state rather than simply thinking intellectually about the concept. When the new sample was placed under the microscope, she described the movement as calm and smooth, with the red cells appearing more regular in shape. She also reported seeing a small amount of bright, sparkling-looking material in the surrounding fluid.
Carrington's description of the film is interesting here because she had originally seen Rebecca's still photographs and had not known what to make of them. Watching the video changed her reaction. She wrote that the moving footage seemed to show differences not only in how the cells looked but in the way they behaved as Rebecca's emotional state changed.
[IMAGE — LOVE]
Original sample labelled “Love”.
This is where the experiment becomes more interesting to me than a collection of unusual blood pictures. It was the same woman, on the same day, deliberately moving herself from one strong emotional experience into another while fresh samples were taken along the way. That certainly does not eliminate all the technical variables, but it gives us a very clear question to investigate: if the inner state changes dramatically, what else changes with it?
Fear
For the fear condition, Rebecca recalled an experience in which she had been genuinely frightened and again used EFT to deepen her contact with the memory. According to her account, the cells appeared to move even faster than they had during sadness and then slowed very quickly. She also believed that more white blood cells were visible than in the previous samples. Rebecca wondered whether the rapid change might somehow reflect an adrenaline response, although that was her interpretation rather than something the microscope itself could establish.
[IMAGE — FEAR]
Original sample labelled “Fear”.
This is the point where it becomes useful to leave Rebecca's experiment for a moment and look at physiology that has been tested under controlled conditions. Fear and psychological stress do not remain politely confined to the mind. They alter autonomic activity and cardiovascular function, and laboratory studies show that even brief periods of mental stress can change measurable properties of the blood.
In one study, 44 healthy young adults were randomly assigned either to twenty minutes of a deliberately frustrating cognitive task or to quiet rest for the same period. Compared with the control group, participants exposed to the stressful task showed increases in heart rate and blood pressure, but also in haematocrit and haemoglobin. Their plasma volume decreased, while plasma viscosity and estimated whole-blood viscosity increased.
A separate laboratory study involving 22 men followed participants through a baseline period, ten minutes of mental stress and thirty minutes of recovery. Haematocrit and whole-blood viscosity rose progressively during the stress period and then gradually moved back towards baseline during recovery.
So the broad idea that psychological state can affect what is happening in the blood is not particularly controversial. What remains unanswered is far more specific: do sadness, fear, love or other emotional states produce reliable and repeatable visual patterns of the kind Rebecca believed she was seeing under dark-field microscopy?
That is a very different question, and I think keeping those two things separate makes the experiment more interesting rather than less.
The sample that apparently silenced the room
After putting herself through sadness and fear, Rebecca decided that her poor system needed something considerably more pleasant. She moved into what she called the energy of the Divine Mother. This was her own spiritual language for a nurturing aspect of the Divine, and she explained that someone from a different tradition might approach a similar state through Jesus, the Holy Spirit, Buddha or another spiritual framework. What mattered to her was deliberately entering a powerful experience of love, connection and what she personally understood as Divine presence.
Rebecca described strong waves of sensation throughout her body and tears of joy. When the new sample appeared on the screen, she wrote that the room became completely silent. She described the fluid around the cells as unusually clear, the movement as calm and gliding, and a large amount of bright or sparkling-looking material between the cells. She also reported that some white blood cells appeared to contain bright centres which seemed to pulsate “almost like a little heartbeat”, while a number of red cells appeared almost heart-shaped. These are Rebecca's observations and language, not established microscopic markers of a spiritual state.
[IMAGE — DIVINE MOTHER / DIVINE SOURCE]
Original dark-field image from the spiritual-state phase of Rebecca Marina's experiment.
The microscope did not, unfortunately, pop up with DIVINE ENERGY DETECTED — PLEASE WAIT. Biology remains annoyingly reluctant to provide subtitles. 😁 Rebecca interpreted what she saw through her own belief system, which is perfectly understandable but does not turn that interpretation into a laboratory finding.
Carrington, who watched the documentary rather than relying only on the photographs, described the changes shown during the Divine Source section as appearing even more striking to her than those associated with the other emotional states. At the same time, she explicitly warned that the film should not be presented as scientific proof of Divine influence or of EFT. Her view was that the images were an interesting possibility for future research rather than a scientifically validated finding.
I actually like that position. We don't need to decide immediately what an observation means simply because we have seen something interesting. Observation can come first; explanation can wait.
The sample that was already outside the body
One of the stranger observations came during Rebecca's transition from sadness into love. According to her account, the previous sadness sample had been left under the microscope while she was doing EFT and moving herself into the love state. She reported that the already-drawn sample began to change as well, despite no longer being inside her body, and interpreted this as evidence that she somehow remained connected with it.
This is where we move onto much thinner ground. A fresh blood sample beneath glass changes naturally over time. Cells settle, fluid conditions alter and temperature, evaporation and pressure can affect what is seen. Rebecca's experiment did not control those factors, so this observation cannot establish that her emotional state influenced blood outside her body.
But it does raise a testable question. If someone genuinely wanted to investigate whether directed intention affected separated samples, there is no reason we couldn't design an experiment using multiple samples, controlled timing and temperature, blinded conditions and automated image analysis. Then we could find out whether any difference remained after ordinary physical explanations had been accounted for.
Until that is done, I am very comfortable saying we do not know. “We don't know” is not a disappointing answer. It is simply the point at which curiosity is supposed to turn into investigation.
What we already know: psychological state does not stay only in the mind
Even if every unusual feature in Rebecca's microscope images eventually turned out to have a perfectly ordinary technical explanation, that would not change something we already know from much stronger research: psychological state can influence physical biological processes.
One of the clearest examples is wound healing. In a classic study, 13 women caring for relatives with dementia received small standardised biopsy wounds and were compared with 13 women matched for age and family income. The wounds in the caregivers took an average of 48.7 days to heal, compared with 39.3 days in the control group. The researchers also found differences in immune responses involving peripheral-blood leukocytes.
Another study looked at 42 married couples during two separate admissions to a research unit. During one visit the couples had a structured supportive interaction; during the other they discussed a disagreement. Their experimental blister wounds healed more slowly after the conflict discussion than after the supportive interaction. Even more strikingly, couples who showed consistently higher levels of hostile behaviour healed at around 60% of the rate of couples who showed lower hostility, and differences were also seen in inflammatory cytokine activity.
What I find extraordinary about these studies is that the physical injury itself was standardised. What differed was the psychological and relational environment around the person. Chronic caregiving stress in one experiment and the quality of interaction between two people in another were associated with differences in the pace of tissue repair.
That does not mean one argument “causes illness”, nor does it mean that feeling worried for a few days somehow stops the body from healing. Biology is far more complicated than that. But it does make it increasingly difficult to treat emotional and relational experience as something happening exclusively in the head while the rest of the body gets on with completely unrelated business.
EFT gives us another interesting piece of the puzzle
EFT belongs in this story for a simple reason: it wasn't added afterwards to make Rebecca's observations fit a theory. It was part of what she was doing from the beginning.
There is now controlled research looking at EFT alongside physiological measures. A randomised controlled trial involving 83 participants compared a one-hour EFT intervention with supportive interviewing and no treatment. The EFT group showed a 24.39% reduction in salivary cortisol, compared with reductions of around 14% in each of the two comparison groups; the difference was statistically significant. In that original study, the cortisol change also accompanied improvements in reported psychological distress.
A later direct replication used 53 participants randomly allocated to EFT, psychoeducation or no treatment. The EFT group showed a larger cortisol reduction than in the original study — 43.24% — and this decrease was significantly greater than the reduction seen after psychoeducation. However, the difference between EFT and the no-treatment group was not statistically significant, and unlike the original study, the cortisol changes were not mirrored by participants' own reports of psychological distress.
That distinction matters. These studies do not validate Rebecca's microscope images, and they do not tell us that every subjective emotional shift produces one predictable biological response. What they demonstrate is something more modest and still very useful: an intervention designed to change emotional state can be studied alongside measurable changes in physiology.
Which brings us remarkably close to the question Rebecca was asking in a much more informal way.
Why this caught my attention as a Biodecoding practitioner
In Biodecoding, I am not interested only in what happened to a person. I am interested in how what happened was experienced, because those two things can be very different.
Two people can go through a divorce. One experiences it as enormous relief and finally feels able to breathe. The other experiences abandonment, rejection and the terrifying feeling that there is no safety anymore. Two people can lose a job; one thinks, “Thank goodness, I hated it anyway,” while the other experiences the same type of event as “There will be no money, I might lose my home and nobody is going to help me.”
The event on paper may be similar. Internally, those are two entirely different experiences.
That is why someone telling me, “I had a very stressful year,” gives me only the beginning of the story. I want to understand what that stress meant to them. Was it fear, separation, helplessness, humiliation, feeling trapped, loss of control, lack of support, needing to protect somebody, or something completely different?
Very often, someone will tell me calmly that a particular event happened twenty years ago and that they are “completely over it”, while their body appears to have received a slightly different memo. Their breathing changes, the jaw tightens, the shoulders rise, the voice shifts or a hand quietly moves towards the stomach.
That does not automatically mean an event from twenty years ago is causing today's physical symptom. It means something simpler and still very useful: bringing that story into awareness can change the person's state now.
And that is why Rebecca's experiment fascinated me. She deliberately changed the state and then looked at the body.
The question behind the experiment
Experiments like this tend to push people very quickly towards one of two extremes. Someone sees the photographs and says, “There you are — proof that love changes blood, that Divine energy is visible and that intention works at a distance.” Someone else notices that it was not a controlled study and decides that the entire subject can therefore be thrown in the bin.
Neither response is particularly satisfying to me.
Rebecca's experiment does not establish that sadness creates teardrop-shaped red cells, that love has a unique microscopic signature or that spiritual intention can alter blood outside the body. At the same time, calling the underlying idea ridiculous ignores what controlled research already tells us. Psychological state can alter blood viscosity and haemoconcentration. Chronic stress can affect wound healing. The emotional quality of interactions between people can be associated with changes in inflammatory signalling, and interventions aimed at emotional state can be studied alongside endocrine changes.
So the broader proposition — that an emotional state can be accompanied by measurable biological change — is not especially radical. What remains unknown is the specific proposition raised by Rebecca's images: whether distinct emotional states produce consistent and repeatable changes in the morphology or movement of fresh blood under carefully controlled dark-field microscopy.
That is the unanswered part, and to me that is precisely what makes the experiment interesting.
What would happen if we repeated it properly today?
More than two decades have passed since Rebecca carried out these observations, and technology gives us far better ways of asking the question now. I would genuinely love to see the basic idea repeated without trying to prove Rebecca right or wrong before the experiment even began.
Imagine a decent number of participants, with the same method of blood collection each time, identical slides, the same delay between sampling and imaging and controlled temperature and preparation. Emotional conditions could be introduced in random order, with several samples taken from each participant, while the people analysing the footage remained blind to whether they were looking at sadness, fear, love or a neutral control. Instead of relying on an observer saying that cells looked calmer or faster, software could objectively measure cell movement, shape, aggregation and spacing. Alongside the microscope imaging, we could record established measures such as heart rate, HRV, blood pressure and cortisol.
Perhaps every dramatic dark-field difference would disappear once the conditions were controlled, which would be useful information. Perhaps a smaller but repeatable pattern would remain. Perhaps microscopy would turn out to tell us very little, while another physiological measure revealed something nobody in Rebecca's room had thought to look for.
Any of those results would be interesting because the purpose of asking a question is not to prove what we already want to believe. It is to find out what actually happens.
So how far through the body does a state go?
This is the question Rebecca's experiment has left me with.
If minutes of psychological stress can change haematocrit and blood viscosity, if chronic stress can slow the repair of a standardised wound, and if the quality of an interaction between two people can be associated with measurable differences in inflammatory signalling and healing, then emotion is clearly not an isolated mental event. When psychological state changes, the nervous system, circulation, endocrine signalling and immune activity can change with it. We can already measure at least some of those effects.
What we cannot yet say is whether Rebecca's dark-field images captured another reliable expression of that same mind-body relationship.
And that leads me to a much more personal question. If I replay the same fear, anger or hurt day after day, what state am I repeatedly asking my body to live in? If the thought of one particular person can still change my breathing, tighten my stomach or make my heart race twenty years later, what else may be shifting in that moment that I cannot consciously feel? And if one day I can remember exactly the same experience without my entire system behaving as though it is happening again right now, what changes alongside that?
This is not about blaming anyone for illness, nor is it about suggesting that we can simply think ourselves healthy. Human biology is vastly more complicated than that. Genetics, infection, injury, environment, age, lifestyle and countless other factors matter, and none of them disappears because we start talking about emotion.
Nor does changing an emotional response mean rewriting history. If someone hurt you, they hurt you. If something frightened you, it frightened you. If you lost someone, no emotional work makes that loss insignificant.
But perhaps I can remember what happened without asking my body to enter exactly the same battle every single time.
And maybe that is why Rebecca Marina's unusual little experiment has stayed in my mind. She took something we normally cannot see — a deliberate change in emotional state — and tried to look for its reflection in something we can.
We cannot know from this experiment whether Rebecca interpreted every image correctly, whether emotion caused the visual differences she observed, or whether those differences would survive properly controlled testing today. That is precisely why I would love to see the experiment repeated rather than either accepted as proof or dismissed and forgotten.
Because one thing we already know is that emotion is not simply an idea floating around in the head.
The body participates.
So perhaps the most interesting question was never whether love can make a blood cell sparkle. Perhaps it is something much bigger:
When my inner state changes, how much of me changes with it?
Rebecca didn't give us the final answer, but she certainly put a bloody interesting question under the microscope.
And yes, that pun is absolutely staying. 😁🩸
Sources
Marina R. EFT research: Emotions affect red blood cells. EFT Universe. https://eftuniverse.com/research-studies/informal-and-unpublished-research/eft-research-emotions-affect-red-blood-cells/
Carrington P. Review: The Power of Emotions in Our Blood (DVD). Mastering the Practice of EFT and Meditation. https://masteringeft.com/masteringblog/review-the-power-of-emotions-in-our-blood-dvd/
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Church D, Yount G, Brooks AJ. The effect of emotional freedom techniques on stress biochemistry: a randomized controlled trial. J Nerv Ment Dis. 2012;200:891–896. https://doi.org/10.1097/NMD.0b013e31826b9fc1
Stapleton P, Crighton G, Sabot D, O'Neill HM. Reexamining the effect of emotional freedom techniques on stress biochemistry: a randomized controlled trial. Psychol Trauma. 2020;12:869–877. https://doi.org/10.1037/tra0000563
Disclaimer: This information is for educational purposes only and should not be considered medical advice. Please consult with a qualified healthcare professional for any health concerns.
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