Back in the day, the early man would run for very long distances in areas that were open. They need to find a way to survive the scorching sun and cool the brains. As a result, evolution triggered the increase of the sweat grand, which created room for expansion of the brain and provided the cooling effect. Human beings are the most unique animals found on planet earth. One of the unique and natural biological process in humans is sweating. This is what keeps you cool and makes humans different from the other animals. Most animals have the capacity to retain heat, while humans are designed to lose heat. Sweating provides cooling, which allows you to go for long distances at great speeds. As a matter of fact, we can outrun most animals, since they would overheat in such conditions.
Daniel E. Lieberman, a Harvard evolutionary biologist, a human can beat a horse in a 26.6-mile race, when the temperatures are high. The International Hyperhidrosis Society has also established that we have 2 to 4 million sweat glands in the body. Dr. Nina G. Jablonski, American Professor at Pennsylvania State University, our large brains are responsible for the evolution from apes to humans. However, the brain would not have expanded if we did not have a sweaty skin. Approximately 2 million years ago, that was when the human evolution took a significant turn and accelerated. This is the period when there were primates that were not longer apes showed up in the Savannahs of East Africa. These are believed to have been the early human beings and they used to run in open areas for long distances. When the brains expanded, we got the capacity to plan and as such this is when people were dispersed from the continent of Africa. With this in mind, you should not find sweating annoying, were it not for the sweat, we probably would still be apes, somewhere in the wild.

The human body has two main types of sweat glands:

Apocrine This type of sweat gland is prominent in areas where there are hair follicles. These sweat glands are commonly found in the anal-genital area as well as the armpits. Usually these glands do not end in pores; instead they are in the form of hair follicles. These sweat glands tend to produce a thicker fluid and when it comes into contact with bacteria they produce a foul smell.

Eccrine
These are the most common types of sweat glands and are found in most parts of the body, including the soles of your feet and the palms of your hands. The Eccrine sweat glands are responsible for moderating core temperature and prevent overheating and also help in cooling the skin.

If you suffer from hyperhidrosis, this means that the sweat glands are overly active and this cause too much sweat to be produced. Several stimuli like physical and emotional stress intensify this overreaction. Some food like caffeine or alcohol may also provoke the sweat glands to overact.