The barometer drops, gray clouds move in outside, and your head grows heavy before the first raindrops even fall. A familiar sensation — but behind it lies not mysticism, but concrete physics that affects some people noticeably while passing others by without a trace.
Everyone knows someone who "feels rain in their knees," or a colleague who works at half capacity on overcast days and complains of migraines. Emergency responders confirm: on days with sharp pressure swings, call volume rises.
Yet the International Classification of Diseases has no diagnosis called "weather sensitivity," and scientific studies produce contradictory results. Some find a link between atmospheric pressure and wellbeing; others don't. Let's sort out what's confirmed by science and what remains subjective observation.
What "Low Pressure" Actually Means
Normal atmospheric pressure is 760 mmHg (1,013 hPa) at sea level. But "normal" is a geographic concept: Moscow's average pressure runs around 747–749 mmHg, since the city sits at elevation.
Every region has its own baseline, and the body adapts specifically to it.
Pressure is considered low when it deviates 10 or more units below the local norm. During a deep cyclone, the barometer in central Russia can drop to 720–730 mmHg — a substantial difference.
The rate of decline matters most: a gradual drop of 5–7 mmHg over 24 hours is tolerated calmly, while a sharp fall of 15–20 mmHg within a few hours is an entirely different matter.
What Happens to the Body When Pressure Drops
The mechanism behind low pressure's effects on the body isn't a mystery — it's basic physics.
- Oxygen becomes scarcer
More precisely, the percentage of oxygen in the air stays the same (around 21%), but under lower pressure, air is thinner, and each breath draws fewer O₂ molecules into the lungs. Mild hypoxia sets in — oxygen deprivation. The body compensates through faster breathing and heart rate, but in the early stages a person may feel lethargic, drowsy, and less able to concentrate.
- Gases in the body expand
The body isn't a sealed vessel. Air and gases sit in the intestines, nasal sinuses, and joint cavities. When external pressure drops, they expand slightly — following the same laws that make a balloon swell at altitude. Hence the sensation of head pressure, joint discomfort, and bloating.
For people with chronic sinusitis, air expansion in the sinuses can cause a pressing pain around the forehead and bridge of the nose.
- Tissues swell mildly
Lower external pressure means less compressive force on the body's surface. Fluid in tissues redistributes slightly more freely, which can produce mild swelling — especially noticeable in those already prone to fluid retention.
Who Feels the Swings Hardest
A healthy, fit person usually doesn't notice atmospheric pressure fluctuations. Their blood vessels are flexible, their autonomic nervous system functions properly, and compensatory mechanisms kick in quickly and quietly. Problems arise when a weak link exists somewhere in that system.
People with cardiovascular disease. For those with hypertension, dropping atmospheric pressure can paradoxically raise blood pressure — vessels constrict, attempting to compensate for the external thinning. For those with hypotension, it's the reverse: already-low blood pressure drops further, bringing weakness, dizziness, and darkening vision.
Cardiologist Yuri Konev, in a comment for NEWS, noted that people with impaired autonomic regulation react most sharply — their bodies simply can't adjust in time.
People with chronic joint conditions. The classic "knees that feel rain coming." Australian researchers monitored 200 patients over three months and found that knee pain intensified slightly with changes in atmospheric pressure and temperature.
The mechanism likely relates to expansion of joint fluid and inflamed tissue, but the effect's scale is small — not universal, not every time, not catastrophic — more of background discomfort.
People with migraines. Japanese researchers asked subjects to keep headache diaries for a year and cross-referenced them with weather data. The result: migraine attacks coincided with days of dropping atmospheric pressure.
An international team from Taiwan, the US, and the UK also found a correlation — with a caveat: different climate zones triggered migraines through different weather factors. In some places, pressure; in others, wind; in others, an approaching cold front.
People with respiratory conditions. Bronchial asthma, chronic obstructive pulmonary disease — under lower pressure, breathing is objectively harder, since each breath delivers less oxygen. This isn't a subjective sensation — it's a measurable physical fact.
What Science Says Overall
Here's where things get interesting — because science doesn't give a clear-cut answer.
A 2016 meta-analysis covering 11 studies and data from 314,385 patients couldn't prove a link between atmospheric pressure and heart attack frequency. Japanese researchers spent 10 years searching for a correlation between cardiac arrests and atmospheric conditions — and also found none.
Harvard researchers found no pattern between rainfall and frequency of doctor visits.
Meanwhile, emergency call statistics in Russian cities consistently show a rise on days with sharp pressure swings. A contradiction? Not quite. Large epidemiological studies average data across hundreds of thousands of people, and individual sensitivity gets lost in the aggregate. In real life, it's not "the population" that reacts — it's a specific person with a specific set of chronic conditions.
The Anticipation Effect: When Your Head Hurts "Preemptively"
A separate phenomenon is the nocebo effect in weather sensitivity. A person checks the forecast, notices overcast skies, recalls past episodes of feeling unwell — and the body "obligingly" reproduces familiar symptoms.
This isn't faking: the brain genuinely triggers physiological responses in anticipation. Psychologists call this apophenia — the tendency to find patterns where none may exist.
Testing yourself is simple: if feeling unwell always coincides with checking the barometer or reading the forecast, but never occurs when you learn about the pressure change retroactively, the cause is more likely anticipation than the atmosphere itself.
The City and Pressure: Floor Height Matters
A little-known nuance: residents and workers in high-rise buildings may feel the swings more sharply. Atmospheric pressure decreases with altitude — roughly 1 mmHg every 12 meters. On the 30th floor, pressure already sits 7–8 mmHg below ground level. Add a general cyclonic drop on top, and the cumulative deviation from your body's usual baseline becomes more significant.
Evgeny Mashkovsky, commenting on Moscow's record pressure drop in autumn 2023 for Rossiyskaya Gazeta, noted that office workers in high-rises may suffer from weather changes more often, especially those with vascular issues.
Pressure Doesn't Act Alone: Weather Comes as a Package
Atmospheric pressure rarely operates in isolation. Its drop is usually accompanied by rising humidity, falling temperature, strengthening wind, and reduced sunlight. Together, all of this creates that heavy day when you're sleepy, your head throbs, and your joints ache.
Low temperature increases blood viscosity and strains the heart. High humidity hinders heat release through sweating. A sunlight deficit reduces serotonin production, producing low mood and apathy. Weather affects wellbeing through this whole combination, and isolating pressure's individual contribution to the cocktail is a task science handles with mixed success so far.
What to Do About It
A few practical observations for anyone who notices sensitivity to pressure swings.
Watch the forecast — not for anxiety, but for planning. If a sharp pressure drop is forecast tomorrow, it's reasonable to avoid scheduling an intense workout or important negotiations that day. Your body will already be adapting — no need to overload it further.
Movement helps. Paradoxically, light physical activity (a walk, a stretch, easy exercise) works better than lying on the couch during low pressure. Muscular activity speeds up blood flow and helps vessels adjust faster.
Water is a simple remedy. Dehydration amplifies hypoxia symptoms, and under low pressure the body is already working with a deficit. A glass of water won't cure weather sensitivity, but it removes one aggravating factor.
If every cyclone turns into an ordeal of severe headaches, blood pressure swings, or heart pain — that's a reason to investigate not the weather, but what's behind those symptoms. Weather sensitivity isn't a disease in itself — it's a signal that some system in the body is operating at its limit, and the pressure change simply exposes that weakness.
