Why Do Dizziness, Chest Tightness, and Joint Pain Occur Before a Typhoon? An Explanation of Rapid Pressure Drops and “Weather-Related Illnesses”
Key SummaryOn the day before a typhoon makes landfall, many people act like a “human weather forecast”: migraines flare up, drowsiness and chest tightness set in, and old joint injuries start to ache. Pets such as cats and dogs may also become restless. This is not merely psychosomatic; low atmospheric pressure can affect physiological mechanisms.
A Typhoon Is an Enormous “Low-Pressure System”
Standard atmospheric pressure is approximately 1,013 hectopascals (hPa), while the central pressure of a mature typhoon can drop as low as 920–960 hPa. In areas affected by the outer circulation of a typhoon, atmospheric pressure can plunge by 10–30 hPa in just a matter of hours—equivalent to suddenly ascending several hundred metres in an elevator. At the same time, relative humidity can soar above 90%.
How Does Low Pressure Trigger “Weather-Related Illnesses” in the Human Body?
- Inner-ear pressure receptors and migraines: The vestibular organs in the inner ear are extremely sensitive to changes in atmospheric pressure, much like the sensation of ears popping during an airplane takeoff or landing. A sustained drop in pressure stimulates these receptors and triggers sympathetic nervous activity through the vestibular nerves. This causes cerebral blood vessels to constrict and then dilate, potentially inducing migraines, dizziness, and tinnitus.
- Slight vascular expansion and pain in old joint injuries: When external atmospheric pressure falls, pressure inside the body’s tissues becomes relatively higher. Joint capsules and damaged soft tissues may swell slightly and press against surrounding pain-sensitive nerves. Combined with high humidity and a temperature drop, rheumatic arthritis or old fracture injuries may sound the alarm at the same time.
- Lower partial pressure of oxygen and chest tightness or drowsiness: Low atmospheric pressure combined with high water-vapour pressure causes the partial pressure of oxygen in a given volume of air to decline slightly. People with weaker cardiopulmonary function or conditions such as asthma or coronary heart disease may therefore experience chest tightness, shortness of breath, or unusual drowsiness.
Why Do Cats, Dogs, and Birds Behave Unusually Before a Typhoon?
Animals are several times more sensitive to infrasound and subtle pressure changes than humans:
- When a typhoon violently stirs the ocean and air, it generates typhoon infrasound (“tsunami sound” or “cyclone infrasound”) at frequencies below 20 hertz. This sound travels to land roughly ten hours or more ahead of the storm at a speed of 340 metres per second.
- Cats hiding in wardrobes or under beds, and dogs barking restlessly or refusing to go outside, are reacting to infrasound that humans cannot hear and sensing the sharp pressure drop. Keep doors and windows closed, draw the curtains, and provide pets with a quiet, sheltered place to help calm them.