That "rainy season sluggishness"? It's not just the weather. Here's how acupuncture can help.

Every year around this time—heavy limbs, fuzzy head, old injuries aching, restless sleep.

If you're thinking "it's just the rainy season, nothing I can do about it"—there's actually more to the story. And there's growing evidence that acupuncture can help.

Let's look at what's really going on, with a little science but not too much jargon.

3 reasons rainy season messes with your body

① Barometric pressure → inner ear → autonomic nervous system

Low-pressure systems roll in one after another during the rainy season. When barometric pressure drops, the pressure sensors in your inner ear sense something's off, and your brain misinterprets it as stress. The result: your sympathetic nervous system goes into overdrive, blood vessels constrict, circulation suffers, and you get headaches, fatigue, and dizziness.

The evidence: Multiple studies have linked pressure changes to headaches. In weather-medicine research, the risk of migraine attacks during low-pressure systems increases by about 1.2–1.5× (Prince et al., 2004; among others).

② Humidity + failed thermoregulation

High humidity means sweat doesn't evaporate well, trapping heat in your body. Your autonomic nervous system works overtime to regulate temperature. Eventually, it gets exhausted—and the smooth switching between sympathetic and parasympathetic modes breaks down. That's what people call "autonomic imbalance."

③ Lack of sunlight → serotonin drop

Cloudy days mean less sun exposure. Less sun means less serotonin synthesis. And since serotonin is a building block for melatonin (your sleep hormone), you get a double whammy: low mood + poor sleep quality.

So where does acupuncture come in?

Acupuncture can potentially address all three of these mechanisms.

✅ Autonomic regulation (evidence level: high)

Needle stimulation affects the hypothalamus-pituitary-adrenal (HPA) axis via peripheral nerves and has been shown to shift the body toward parasympathetic dominance.

• A 2013 systematic review (Lee & Fan, Autonomic Neuroscience) confirmed that acupuncture significantly improves heart rate variability (HRV) and increases parasympathetic activity.

• In plain terms: when rainy season has your sympathetic system running hot, acupuncture can help cool it down.

✅ Blood flow improvement & pain relief (evidence level: high)

Acupuncture dilates local blood vessels and activates the brain's descending pain-inhibitory pathways, which can ease old injuries and headaches.

• The analgesic effect of acupuncture has been confirmed by brain imaging studies, involving the release of endogenous opioids like β-endorphin (Zhao, 2008 Progress in Neurobiology).

✅ Serotonin boost (evidence level: moderate to high)

Both animal and human studies suggest acupuncture promotes serotonin synthesis in the brain.

• Stimulation of points like HT7 (Heart 7) and PC6 (Pericardium 6) has been reported to increase serotonergic neuron activity (Chang et al., 2014 Neuroscience Letters).

• With less sunlight lowering your serotonin levels during the rainy season, giving it an acupuncture-assisted bump is a reasonable strategy.

What to expect when you go for treatment

When you visit an acupuncturist for rainy-season issues, the key isn't just naming your symptom—it's describing how it behaves.

Saying "I have a headache" is fine, but saying "my head gets heavy before a low-pressure front moves in, and it's worse on rainy days" gives the practitioner much more to work with. The same "headache" could be pressure-driven, neck-tension-driven, or eye-fatigue-driven, and each calls for a different approach.

For this time of year, the most effective combo is often retained needles+ moxibustion.

• Retained needles: Needles are inserted and left in place for several minutes, gradually nudging your parasympathetic system into the driver's seat.

• Moxibustion: Dried mugwort is burned to gently warm the body. Since high humidity makes your surface temperature drop more easily, this is a perfect match for the rainy season. There's also a "gentle moxa" method that won't burn, so even if you dislike heat, it's worth asking.

One lesser-known tidbit: some experienced practitioners say needles feel different during the rainy season. Changes in skin electrical resistance due to humidity can affect how a needle "catches." A seasoned acupuncturist adjusts their technique accordingly—a subtle skill you only get with hands-on treatment.

Things you can do right now at home

🔹 Warm the back of your neck

For rainy-season headaches and brain fog, a warm towel on the back of your neck (around the base of the skull) works surprisingly fast. It boosts circulation and helps you feel clearer.

🔹 Press LI4 (Hegu / 合谷)

On the back of your hand, between the thumb and index finger. Press firmly but comfortably for 1–2 minutes. Good for headaches and general fatigue. In Japanese it's called gōkoku—also known as the "tiger's mouth" point.

🔹 Press ST36 (Zusanli / 足三里)

Four finger-widths below your kneecap, just outside the shinbone. Pressing here is said to regulate digestion and get the body's energy moving. A go-to point for rainy-season sluggishness.

🔹 Massage your ears

Your ears are packed with acupoints mapped to your whole body. Gently pulling and circling the ear with your fingers can trigger a surprising amount of relaxation.

Bottom line: rainy season isn't "just something to endure"

Barometric pressure, humidity, and lack of sun—three factors that throw your system off balance. But understanding the causes means you can do something about them.

Acupuncture blends over a thousand years of practice with modern evidence backing its effects. Think of it as tradition–science hybrid care.

That said, we know dragging yourself to a clinic in the rain isn't always appealing. That's where Kiyo Harikyudo comes in—we provide home-visit acupuncture across Osaka City and Osaka Prefecture, so you can get treatment without stepping outside.

Our Body Remake Acupuncture (体リメイク鍼) course is designed to tackle everything from that heavy rainy-season fatigue to chronic issues, all in one comprehensive session.

Book via LINE or Instagram DM.

This article is for general informational purposes and does not guarantee specific treatment outcomes. If you have concerns, please consult a licensed acupuncturist or physician.