Eccrine sweat glands occur over most of the body and open directly onto the skin's surface. Apocrine glands open into the hair follicle, leading to the surface of the skin. Apocrine glands develop in areas with many hair follicles, such as on the scalp, armpits and groin. Eccrine sweat glands are involved in hyperhidrosis, though apocrine glands may play a role as well.