The answer is simple, but not easy. The body isn’t designed to sweat constantly! Sweat has an important function in the body, helping cool us down and then protecting us from dehydration. You can learn more about this phenomenon by reading up on the thermoregulation theory of sweating here: http://www.swellingunderarms.co.uk/sweating-your-underarms-a-basics
How do I stop my underarm sweating so much? You’ve probably heard how putting cotton wool under your arms makes you sweat less, but there’s nothing magical about it at all – it’s just a trick learnt by generations of athletes for how to reduce their natural perspiration levels when they were out competing in sports such as running races or swimming competitions where they would be subjected to high levels of heat and humidity conditions during their training sessions or events themselves!