Författare: Michelle Spear Professor of Anatomy University of Bristol

For centuries, people have claimed that their aching joints can predict changes in the weather, often reporting increased discomfort before rain or cold fronts. Given the scale and duration, there is a sense of legitimacy to these anecdotes – but this phenomenon remains scientifically contentious.

From shifts in barometric pressure to temperature fluctuations, many theories attempt to explain how environmental factors might influence joint pain. But is there an anatomical basis for this claim, or is it simply an enduring weather-related myth? Are our joints any more reliable than the Met Office?

At the heart of this debate lies barometric pressure, also known as atmospheric pressure – the force exerted by air molecules in the Earth’s atmosphere. While invisible, air has mass, and the “weight” pressing down on us fluctuates with altitude and weather systems.

Higher barometric pressure often signals fair-weather conditions with clear skies and calm winds, whereas lower pressure typically precedes unsettled weather, such as cloudy skies, precipitation and humidity.

Moveable joints are intricate structures cushioned by synovial fluid, the viscous liquid that lubricates joints, and encased in capsules rich in nerve endings. In healthy joints, these components should allow smooth, pain-free movement. However, when joints are compromised by cartilage damage (as in osteoarthritis) or inflammation (as in rheumatoid arthritis), even subtle changes in the environment may be acutely felt.

One leading hypothesis suggests that changes in barometric pressure may directly influence joint discomfort. When atmospheric pressure drops ahead of storms, it can allow inflamed tissues within joints to expand slightly, increasing stress on surrounding nerves and amplifying pain. Conversely, rapid increases in pressure, characteristic of fair-weather systems, may compress already sensitive tissues, leading to discomfort in some people.

Barometric pressure may influence joint discomfort.
Chuck Eckert / Alamy Stock Photo

Scientific studies offer some support for these claims, though results remain mixed. For instance, a 2007 study published in the American Journal of Medicine found a slight but significant correlation between dropping barometric pressure and increased knee pain in osteoarthritis patients. However, this pattern is not universally observed across all joint conditions.

A 2011 systematic review in Arthritis Research & Therapy examined the relationship between weather and pain in rheumatoid arthritis patients. It revealed highly variable responses: while some people reported increased pain under low-pressure conditions, others noted no change. A few even experienced discomfort during high-pressure fronts.

More recently, a [2019 citizen-science project] called Cloudy with a chance of pain used app-based pain tracking to explore this connection. The study found a modest association between falling pressure and heightened joint pain, but it also highlighted substantial individual differences in how people perceive weather-related pain.

These findings suggest that while changes in barometric pressure may influence joint pain for some, responses are far from uniform and depend on a complex interplay of factors, including the individual’s underlying joint condition and overall pain sensitivity.

Why responses differ

Barometric pressure rarely acts in isolation. Fluctuations in temperature and humidity often accompany pressure changes, complicating the picture.

Cold weather can have a pronounced effect on joints, particularly in people with existing joint conditions. Low temperatures cause muscles to contract and become stiffer, which can lead to reduced flexibility and a greater risk of strain or discomfort.

Ligaments, which connect bones to one another, and tendons, which anchor muscles to bones, may also lose some of their elasticity in colder conditions. This decreased pliability can make joint movement feel more restricted and exacerbate pain in conditions like arthritis.

Cold weather can also cause blood vessels to narrow — particularly in the extremities, as the body prioritises maintaining core temperature. This reduced blood flow can deprive affected areas of essential oxygen and nutrients, slowing the removal of metabolic waste products like lactic acid, which may accumulate in tissues and exacerbate inflammation and discomfort.

For people with inflammatory conditions, the reduced circulation can aggravate swelling and stiffness, especially in small joints like those in the fingers and toes.

Cold also slows the activity of synovial fluid. In lower temperatures, the fluid becomes less effective at reducing friction, which can heighten joint stiffness and make motion more painful, particularly for people with degenerative conditions such as osteoarthritis.

Sudden temperature changes may also play a role. Rapid shifts can challenge the body’s ability to adapt, which might worsen pain in people with chronic conditions. Similarly, high humidity can intensify sensations of heat or dampness in already inflamed areas, further complicating the experience of pain.

However, isolating a single variable – whether humidity, temperature or pressure –proves difficult because of the interplay of overlapping factors.

Responses to weather also depend on individual factors, including the extent of joint damage, overall pain sensitivity and psychological expectations. This variability makes it difficult to link a single meteorological factor to a biological response.

Still, the evidence suggests that people with joint conditions tend to be more attuned to environmental changes, particularly pressure fluctuations.

While the relationship between weather and joint pain remains an imperfect science, the collective evidence indicates that there may be some truth to the age-old belief. For those with chronic joint conditions, shifts in barometric pressure and accompanying weather changes might indeed serve as nature’s warning system – albeit one that’s far from foolproof. Läs mer…

Step into any supermarket or pharmacy, and you’ll find aisles brimming with products designed to make you smell “fresh”, feel “clean”, or somehow achieve a level of “purity” that no human body naturally possesses.

Whole-body deodorants have joined the lineup of intimate washes, douches and steaming kits, with internet searches for these deodorants massively increasing since 2023. All promise to do what your body is already masterfully equipped to handle: keeping itself clean and functioning.

But here’s the thing, your body is not unclean.

Whole-body deodorants are marketed for areas beyond the armpit, most commonly feet and intimate areas – but the premise that these areas are inherently dirty is misleading. In fact, the body is a finely tuned biological system that has been self-regulating for millennia. The notion that you need expensive products to achieve basic hygiene is a fallacy rooted in marketing, not science.

Self-cleaning vaginas

The vagina is one of the most misunderstood parts of the body when it comes to hygiene. Despite its remarkable ability to maintain its own health through a delicate balance of pH and beneficial bacteria, an entire industry exists to sell products that disrupt this natural system.

From douches to scented wipes, these products often cause the very issues they claim to solve, such as infections or irritation.

Central to the vagina’s self-cleaning process is vaginal discharge – a natural and essential function. Discharge consists of water, mucus and cells shed from the vaginal lining, which flush out bacteria, dead cells and debris.

Thanks to this continuous self-flushing mechanism, no internal cleaning, such as douching, is necessary. In fact, such interventions can disturb the vaginal microbiome, increasing the risk of bacterial vaginosis or yeast infections.

Vaginal steaming, a practice promoted by wellness influencers, claims to “cleanse” or “revitalise” the uterus and vagina. Yet there is no evidence of benefit and, in terms of the uterus, reveals a misunderstanding of anatomy. It is unnecessary at best and harmful at worst.

While the vagina takes care of its internal health, the external vulval area does require some attention. Exposed to sweat, urine and natural oils, the vulval skin benefits from gentle daily cleaning with warm water or mild soap.

Male intimate hygiene

For men, the marketing approach differs but remains equally misleading. Products like intimate washes and deodorising sprays are presented as essential for modern grooming. Consider the rise of “ball sprays” (a genuine term) and lotions, which promise to keep the scrotum dry and odour-free.

The scrotum is more than just a protective pouch for the testes; it is also a thermoregulating organ designed to maintain an optimal temperature for sperm production. To achieve this, the scrotum is equipped with eccrine sweat glands.

These glands are small coiled structures located within the dermis of the skin. They function by releasing sweat through ducts that open directly onto the surface of the skin. This sweat evaporates, dissipating heat and helping to cool the scrotum.

Unlike apocrine sweat glands found in areas such as the armpits or groin, eccrine glands do not produce the lipid-rich secretions that can lead to body odour when broken down by bacteria, so scrotum sweat is typically odourless.

While excessive moisture can lead to issues such as fungal infections, these are often managed with breathable fabrics, regular washing and thorough drying – not specialised products.

Ball sweat is typically odourless.
Robnroll/Shutterstock

Feet – the unsung heroes of sweat regulation

Feet, often confined in socks and shoes, are another frequent target of whole-body deodorants and sprays. Feet are not inherently dirty, they are simply hardworking, equipped with about 250,000 sweat glands – the highest concentration of sweat glands in the body.

Like the scrotum, these are eccrine sweat glands, releasing mostly water-based sweat to help cool the feet, particularly during physical activity or in warm conditions.

Feet have around quarter of a million sweat glands.
Brian Jackson / Alamy Stock Photo

Moisture from sweat also reduces friction between the skin and footwear. Additionally, eccrine sweat keeps the skin of the feet supple and prevents cracking, which might otherwise create entry points for infections.

Though sweat from the feet is odourless when trapped in moist, warm environments such as socks or shoes, bacteria on the skin break down sweat components, releasing compounds that cause odour. Prolonged moisture can also lead to fungal infections, such as athlete’s foot and skin maceration, where softened skin becomes more prone to irritation or breakdown.

Managing foot sweat involves supporting the body’s natural processes rather than eliminating them. Daily washing with warm water and mild soap, followed by thorough drying, is essential.

So, the bottom line is, if a company is trying to sell you the idea that your body is inherently unclean, it’s likely not your hygiene that needs fixing. It’s their marketing pitch.

However, if body odour persists despite daily washing, it could signal an underlying medical condition. These conditions deserve sympathetic investigation and appropriate support, not masking with overpriced products that treat only the symptom rather than the cause. Läs mer…

When an 84-year-old man in Hong Kong went to hospital with an enlarged prostate, doctors were startled to see that his skin – and even the whites of his eyes – had turned silver-grey. A deeper investigation revealed silver deposits permeating his tissues, turning him a hue more often reserved for science fiction.

Far from a one-off oddity, in 2007 press reports described Paul Karason as a “blue man” after he attempted to cure sinus and skin problems by ingesting a homemade silver chloride solution – and there are many other examples.

These striking cases reveal a profound truth: our bodies can display the residue of what we consume. The adage “you are what you eat” usually refers to overall health and nutrition, but that phrase can be startlingly literal when our skin takes on unexpected colours.

The cases above illustrate dramatic instances of the condition known as argyria, in which silver particles accumulate in the body.

Silver was once a mainstay in medical treatments for its antimicrobial properties. But modern evidence shows that consuming or absorbing too much can transform one’s skin in ways that seldom fade. In argyria, silver ions circulate through the bloodstream and become embedded in the dermis, a layer beneath the surface where the body cannot easily clear them. This is the layer that tattoo pigments reside in.

Sunlight compounds the effect by triggering a process called photoreduction, which turns silver ions into metallic silver or related compounds. As a result, affected lighter skins adopt a bluish or greyish tinge. And in brown and black skin, the discolouration may appear as a darker grey or slate-blue hue, effectively creating an inadvertent tattoo.

A similar phenomenon, albeit rarer, is chrysiasis, in which gold deposits infiltrate the skin. Historically, gold-based therapies were occasionally prescribed for inflammatory disorders, and in some cases, patients who received these treatments developed a distinctive slate-grey or grey-purple discolouration that, much like argyria, could not be easily undone.

Paul Karason suffered from argyria.

Pigments from the plate

Orange, yellow and red pigments exert the most influence over skin, and orange seems to reign supreme. This shade, often associated with carrots, sweet potatoes and pumpkins, comes from carotenoids, a class of pigments naturally found in plants.

Carotenoid pigments are fat soluble. When consumed, they are absorbed in the small intestine and transported via lipoproteins in the bloodstream to be stored primarily in fat-rich tissues, including the subcutaneous layer of the skin. This storage gives the skin a characteristic golden hue, most notably when carotenoid-rich foods are consumed in high quantities.

Of the many carotenoids found in nature, beta-carotene is the star player: a strong orange tint and high “bioavailability” – the term used to describe drug absorption – make it particularly influential.

Humans metabolise (break down) carotenoids in a selective way. Enzymes in the intestines and liver turn beta-carotene into vitamin A, which is crucial for vision, a healthy immune system and healthy skin.

However, not all ingested beta-carotene undergoes this transformation. Excess amounts remain in their pigment form and are deposited in the skin, particularly in areas like the palms of the hands and soles of the feet, where the thicker layer of skin highlights the pigment’s presence.

Too much beta-carotene can turn your skin orange.
Adisha Pramod / Alamy Stock Photo

The reason the skin turns orange lies in the chemical structure of carotenoids. Beta-carotene’s molecular makeup absorbs light in the blue spectrum, reflecting orange light back to our eyes. Other carotenoids, such as lutein and zeaxanthin (found in leafy green vegetables), which lean toward yellow, are less conspicuous because they are either less abundant in the diet or not as prominently stored in the skin.

Research has shown that a carotenoid-rich diet, which can enhance a healthy golden glow, is often perceived as more attractive than sun-induced tanning. But moderation is key. The 90s juice brand Sunny Delight never really recovered from the controversy of orange-stained Sunny D kids.

Naturally occurring dietary pigments such as anthocyanins, betalains and chlorophyll offer many health benefits, but rarely leave a mark.

Anthocyanins, found in berries, red cabbage and purple carrots, provide the deep reds, purples and blues we associate with these foods. Known for their antioxidant properties, they are water-soluble, meaning they are quickly metabolised and therefore unlikely to leave a mark on the skin.

Similarly, betalains, the pigments responsible for rich reds and yellows, offer detoxifying and anti-inflammatory benefits but are excreted by the body without a visible effect on skin tone. Excess ingestion may, however, cause urinary and faecal colour change.

These colourful tales carry more than an aesthetic message. They highlight the fine balance required in our relationship with the substances we ingest. From wholesome pigments to unintended consequences, they serve as a vivid reminder that while food may be medicine and may be transformative, we are, quite literally, what we eat. Läs mer…