Our skin regulates body temperature by sweating. Although we are not aware of it, this sophisticated natural mechanism keeps us alive, because the body requires a constant internal temperature. But some people do not sweat enough, and, in some cases, this disorder has serious repercussions.
This blog has already included a post on the bothersome problem of excessive sweating (hyperhidrosis) and its treatments. But sweating too little (hypohidrosis) or not sweating at all (anhidrosis) are much more dangerous to health, because the body fails to maintain its proper temperature. The pores of the skin, usually easily seen under a magnifying glass, are virtually invisible in people with these problems. The causes, whether genetic, endocrinological (diabetes, hypothyroidism) or neurological, affect the nerves involved in sweating. Symptoms include dizziness, headache, nausea, trembling, fever and tachycardia. These syndromes have no cure or medication, but fortunately affect few people. The only solution is to hydrate properly and avoid heat stroke by staying in the shade.
Sweating is necessary. Sweating through the skin is the physiological response to an increase in body temperature during physical exercise or because of excessive heat. Sweat evaporation cooling the body is the mechanism by which temperature is regulated. If this mechanism fails even death may result. But some people sweat excessively and, for them, hyperhidrosis is a very annoying problem.
The skin has three types of sweat glands. The most numerous are the eccrine glands, responsible for thermoregulation by sweating. They are distributed over all the skin, but are particularly to be found in palms, soles, armpits and the face; the apocrine glands, primarily located in the armpits, nipples and perineal area, are responsible for body odour. Humans have between two and four million eccrine sweat glands distributed all over the body surface and averaging about 600 per square centimetre. A person can sweat several litres per hour and up to ten litres in a day. Read more
Our genes determine what our skin secretes in sweat and, consequently, how we smell. No two body odours are alike as we all have our own unique “cocktail” of bacteria that break down sweat to release volatile substances. But there are people who do not smell ... and they even use deodorant.
Our body odour develops when skin bacteria degrade certain substances produced by the sweat glands: steroid hormones, fatty acids and sulphur compounds. Our genetic characteristics determine the amount and proportion of each such substance secreted and, consequently, differences in how we smell. However, in a recent UK study of 6 500 women it was found that 2% had virtually no smell because of their particular version of the ABCC11 gene. However, over 75% of these women used underarm deodorant – out of habit. Identifying this genetic trait could lead to odourless people both saving money and reducing their exposure to chemicals. Such studies also open the way for the future application of genetics to the field of personal hygiene.
Alum crystal, used by ancient civilizations, has come back into fashion with the rise of natural cosmetics. It has many properties, including as a body deodorant. How does it benefit the skin? Is the aluminium it contains hazardous?
Alum crystal is a naturally occurring sweet-tasting mineral that looks like translucent glass. It is usually composed of an aluminium sulfate and a sulfate from another metal. The most commercially exploited alum is the hydrated form of potassium aluminium sulfate (potassium alum), which comes from a volcanic igneous rock called aluminiferous trachyte; it can also be manufactured industrially, however. Read more