Most of us know that men can wake up with an erection, and no one treats it as unusual. The same thing happens quietly in women's bodies during sleep. Few people have ever heard of it, and even fewer know why doctors are starting to look at it.
A perspective paper published in February 2026 in the journal Medicina argues that reduced nighttime blood flow to the clitoris may be an early warning sign of cardiovascular trouble in women.
The parallel in men is well established. Erectile dysfunction tends to show up about two to five years before coronary artery disease, giving the body a window where damage can still be caught.
Why the clitoris may spot vascular disease first
The reasoning comes down to pipe size. The arteries that fill the penis are small, around 1 to 2 millimeters wide. In the clitoris, they are smaller still, between 0.7 and 1.1 millimeters.
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When plaque starts to narrow blood vessels across the body, the thinnest ones feel it first. Flow drops in the smallest arteries before anything else gives it away.
The authors from the University of South Carolina and Lund University also pulled together evidence from 54 studies. Women with established cardiovascular disease had 1.51 times higher odds of female sexual dysfunction than women without it.
The review flags a gap, though. Long-term tracking of men's erectile function is extensive. Comparable evidence in women, the authors note, remains limited and heterogeneous.
What a Doppler scan has already shown
In a 2021 study of 230 women, published in Scientific Reports, researchers used color Doppler ultrasound to measure blood flow in the clitoral arteries. Higher vascular resistance there tracked with classic cardiometabolic warning signs.
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Body mass index, waist circumference, triglycerides, fasting insulin, and insulin resistance all moved with the flow readings. Those are the same markers that drive heart disease.
If flow in the clitoris reflects what is happening elsewhere in the circulation, the signal is already there, just not being read.
A biohacker is testing the idea at home
Biohacker Kate Tolo, 30, is tracking her nighttime genital blood flow at home using an internal probe she calls a "techno tampon," according to LADbible. The device dates to 1975 and has barely changed since.
The equipment costs around $15,700 and has to run on a laptop that stays awake through the night. Tolo told LADbible in October 2026 that men's nighttime erections have been studied extensively for decades, while women's are barely measured.
The nighttime measurements are her attempt to find out whether the signal matters in women the way it does in men.
What this means for an ordinary doctor's visit
For now, nighttime clitoral blood flow is a research question, not a test any doctor can order. In men, reduced nighttime erections are already treated as a reason to look harder at the heart.
The Medicina authors argue the same should apply in women. Sexual symptoms, they suggest, deserve to be considered alongside the usual cardiovascular risk factors rather than kept separate.
A woman noticing changes in sexual response, especially alongside things like high blood pressure or rising blood sugar, has reason to bring it up with her doctor. The field just does not yet have a routine clinical test to put behind that conversation.
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This article is made and published by Aksel Kryhlmand, who may have used AI in the preparation.