Sweat is produced by sweat glands in the body, which produce a watery fluid and fluid containing substances such as proteins and lipids. We sweat from up to 5 million sweat glands located all over the skin on our body. However, sweating that is triggered by emotions or stress only happen in certain areas of the body, such as the armpits, palms and head.
How Do We Sweat?
There are two types of sweat glands on the skin: apocrine – found mainly in the armpit area – and eccrine glands, which are found all over the skin surface. The mechanism of perspiration, or sweating, is controlled by the body’s autonomic nervous system – the part of our nervous system which is under involuntary or ‘unconscious’ control. Apocrine glands become active from puberty and are found mainly in the armpits.
The apocrine glands produce sweat when we feel strong emotions, stress, pain or exercise. The sweat from apocrine glands is responsible for producing the smelliest body odour. Sweat produced from the apocrine gland is thought to be linked to the production of chemical communication signals or pheromones. The apocrine glands are situated close to the hair follicle and the secreted sweat fluid contains proteins, lipids and hormones, but very little water.
Eccrine glands are the most abundant type of sweat gland, found all over the skin and start to function soon after birth, releasing a dilute salt solution composed of 99% water. It is the eccrine gland that is responsible for the wet sensation of sweat. Sweat produced from the eccrine glands are key in keeping the body cool via thermoregulation. The eccrine glands produce a far greater volume of sweat compared to the apocrine glands in the armpits.
Did You Know?
- Human skin contains up to 5 million sweat glands
- Humans are one of the sweatiest animals, alongside horses and camel
- Men sweat more than women
- Ancient Egyptians used antiperspirants. Natural antiperspirants in the form of aluminium crystals have been discovered in the tombs of Pharaohs
- The more physically fit you are, the more you sweat
- Sweat from the armpit makes up less than 1% of the normal body sweat
- We tend to sweat more in the afternoon than the morning because our metabolism increases over the course of the day
- We sweat more during the summer as our body works to cool us down in higher temperatures
- We sweat more in our armpits when standing up than lying down
- Overweight people sweat less than lean people because they have a lower density of sweat glands in their skin due to the amount of subcutaneous (under the skin) fat