Sweating, also known as perspiration, is a process in which many organisms, including humans, release water and dissolved salts through the pores of the skin. The main purpose of this process is thermoregulation or temperature control; An organism tends to sweat when overheated. Most of the causes of sweating are related to the return of the body to a healthy and normal temperature. Many organisms tend to sweat when they engage in some form of vigorous activity, such as intense exercise. However, there are many other causes of sweating; some are related to medical conditions, while others may simply be related to stress or emotional strain.
Vigorous physical activity is one of the most common causes of sweating. When one sweats, perspiration covers the skin; This perspiration then evaporates and takes away some of the body's heat. When you exercise particularly hard, your body produces more heat. Consequently, the amount one sweats corresponds to the rigor of the activity in which one is participating.
The causes of sweating also tend to be closely related to the balance of hormones in the body; Conditions or substances that alter hormone levels can cause sweating. People with cancer or some infections sometimes sweat because of the effects such illnesses have on the balance of hormones. Fevers are also among the many causes of sweating, but this is more closely related to an increase in body temperature than hormonal balance. There are some substances that many people ingest on a regular basis that can cause sweating. Caffeine and alcohol are two of the most prominent examples, although many medications can have similar effects.
There are also some psychological causes of sweating. People often sweat when they are scared, nervous, or under significant stress. This is also related to hormones; When one is under emotional stress, the joyous adrenal produces higher than normal amounts of the hormone epinephrine. This, combined with other altered hormone levels, can lead to sweating. Often sweating in response to psychological stress feels cold because it doesn't occur in response to physical heat.
Some people sweat excessively almost all the time. Such excessive sweating is known as diaphoresis or hyperhidrosis, and often has no clear cause. Usually, this form of sweating is centered on the palms of the hands and under the arms. Because it can smell and soak into clothing, it can often be an embarrassing condition.