When was the last time you thought about your sweat glands? Sweat is actually pretty cool. It keeps you from getting too hot, guards against bacteria by making the skin acidic, and even drains away extra fluid and electrolytes from the blood. Hello to night sweats after a heavy night of drinking! There are 2 main types: apocrine and eccrine. Sometimes the eccrine sweat glands get a little too excited about their cushy job, and ta-da: hyperhidrosis happens! These lucky people get extra sweaty when their sympathetic nervous systems kick into gear.