Monitoring One's Health with Sweat Evaporation and Production

Most of the time, we might find ourselves in a sweat because of the hot weather or if we are in a dreadful situation. However, sweating or perspiration is a normal condition of the body and is considered as an integral aspect of human survival. According to Sweat Help, sweating is the body’s coolant, which protects us from overheating. The body has two to four million sweat glands and the majority of them are called “eccrine” sweat glands, which are commonly found in the soles of the feet, the palms, the forehead, the cheeks, and the armpits. The sweat that the eccrine glands secrete is usually odorless and clear, but it is essential in the control of body temperature since it allows heat loss through evaporation. On the other hand, “apocrine” glands are found in the armpits and genital region. These glands secrete a thick fluid. If this fluid makes contact with the bacteria on the skin’s surface, it produces a potent smell which is also known as “body odor.” Moreover, aside from being the body’s natural coolant, sweat also plays an important role in health tracking and monitoring.

Biosensors ‘Bandage’

Sweat is a biofluid that contains a lot of information about a person’s medical history. This is why researchers from the American Chemical Society decided to create a biosensor ‘bandage’ that could help healthcare providers unlock the health monitoring potential of perspiration and use it to take a comprehensive look into patients' medical information. Science Daily recently reported that news about the said biosensor device was also included in ACS’ journal called Analytical Chemistry. According to the report, the researchers focused on developing tools that could effectively collect and analyze sweat, aside from the temporary tattoos or microfluidic devices that typically require wires, electronics, or other sophisticated structures. They decided to create a wearable biosensor similar to a bandage which would collect sample sweat and use a color-changing assay that could quantify various components.

The researchers consisted of Tailin Xu, Li-Ping Xu, and Xueji Zhang. They coated their device with a flexible polyester film that contained a super-hydrophobic silica suspension. The American Chemistry Society also added on their website that the researchers etched microwells into the silica layer which could collect the sweat and, at the bottom of these microwells, they put dyes that could change color with pH or a concentration of chloride, glucose, or calcium. The team also included adhesive backing and placed the biosensor bandage on their patient’s skin. Through the changing of the colors in the bandage, the researchers managed to analyze the colors with a cell phone and they determined the sweat pH of their patient was 6.5-7.0, with a chloride concentration of about 100 mM and traces of calcium and glucose. After this discovery, the team shifted their focus onto working on the sensitivity of the biosensor device.

Sweat as a Health Monitor

Aside from this biosensor technology, researchers from the University of Cincinnati also claimed to develop the world’s first wearable sensor which would be essential in monitoring a person’s health. The News Daily reported that this wearable technology has a similar size of a band-aid and features a portable sensor which could help doctors keep track of their patient’s medical conditions over time. The researchers also looked at the other biofluids such as saliva, tears, and intestinal fluid, but their study concluded that sweat bears the most promise in health tracking. They found that perspiration provides similar information to blood, but the only difference is that using sweat as a way to track one's health condition is non-invasive and it takes a shorter amount of time. Sweat is a product from the interstitial fluid, which could be found between our body’s cells, explains Nigel Taylor, a retired associate professor of thermal physiology from the University of Wollongong. “The concentrations of stuff contained in the plasma and interstitial fluids are very similar,” said Taylor, as he explained that interstitial fluid comes from plasma, blood’s colorless liquid component.

Health Benefits of Sweating

Other than being the body’s natural coolant and natural health monitor, sweat plays an essential role in a person’s health. According to a report by Wellness Mama, sweating can offer relief from hot flashes and helps in decreasing the risk of having heart attacks. Sure, sweating is sticky and very uncomfortable, but all this unpleasantness has health benefits that are very worth it. As we sweat, the body also experiences detoxification which excretes toxic chemicals in the body such as arsenic, cadmium, and lead. In a study conducted in China, they found out that residents who exercised more had fewer toxins in their body and the sweat that was produced through their exercise allowed for the elimination of the heavy metals in their body.