Hi Tess,
Our face is literally the first place we can clinically sweat through your eccrine glands. Although our body's sweat glands can function before birth, physicians don't consider sweating possible until one full day after birth, with the face being the first place it can occur. For some, it may seem like once the sweating started, it never stopped.
Your face — specifically your forehead and scalp — are covered with eccrine glands. They're part of a series of reactions that end in what we recognize as sweating. In other words, it's very normal to sweat on your face when you're hot, whether it's from sitting outside in high temperatures or exercising. But if facial sweating becomes problematic, or if it occurs constantly or in situations where it shouldn't, like in a cool, indoor environment, perhaps it's time to get to the bottom of the trouble.
A condition known as hyperhidrosis — excessive sweating — can extend to the face. If it is, there are a couple reasons why you may be sweating so much. Primary hyperhidrosis is thought to come from emotional triggers, although exactly why remains a mystery. Secondary hyperhidrosis is the result of another, larger medical condition. A number of illnesses have been linked to hyperhidrosis; malignant tumors, infections, heart disease, Parkinson's disease and hyperthyroidism all have excessive sweating as a symptom.
A physician can make a diagnosis between primary and secondary hyperhidrosis. While treatment of the underlying condition should also clear up secondary hyperhidrosis, your doctor has a number of options to treat a case of primary hyperhidrosis. One of the most prevalent ways of combating hyperhidrosis, including on the face, is the use of aluminum chloride, the main ingredient in antiperspirant.
Perhaps the best way to combat hyperhidrosis is through relaxation techniques. Again, since emotional triggers — especially stress — can cause primary hyperhidrosis, reducing the stress in your life and the way you react to stressful situations may help reduce facial sweating.
-Fidel