secrete sweat. Heatstroke can lead to fatal hyperpyrexia (extreme rise in body temperature). Hidradenitis suppurativa Occurs when the skin and sweat glands become inflamed with swollen lumps. These are typically painful and break open, releasing fluid or pus. The most commonly affected areas are the underarms, under the breasts, and the groin. Hyperhidrosis (also known as polyhidrosis or sudorrhea) is a pathological, excessive sweating that can be either generalized or localized (focal hyperhidrosis); focal hyperhidrosis occurs most often on the palms, soles, face, scalp and axillae. Hyperhidrosis is usually brought on by emotional or thermal stress, but it can also occur or with little to no stimulus. Local (or asymmetrical) hyperhidrosis is said to be caused by problems in the sympathetic nervous system: either lesions or nerve inflammation. Hyperhidrosis can also be caused by trench foot or encephalitis. Milaria rubra Also called prickly heat. Milaria rubra is the rupture of sweat glands and migration of sweat to other tissues. In hot environments, the skin's horny layer can expand due to sweat retention, blocking the ducts of eccrine sweat glands. The glands, still stimulated by high temperatures, continues to secrete. Sweat builds up in the duct, causing enough pressure to rupture the duct where it meets the epidermis. Sweat also escapes the duct to adjacent tissues (a process called milaria). Hypohydrosis then follows milaria (postmiliarial hypohydrosis). Osmidrosis Often called bromhidrosis, especially in combination with hyperhidrosis. Osmohidrosis is excessive odor from apocrine sweat glands (which are overactive in the axillae). Osmidrosis is thought to be caused by changes in the apocrine gland structure rather than changes in the bacteria that acts on sweat. Tumors Sweat gland tumors include: Acrospiroma Aggressive digital papillary adenocarcinoma Apocrine gland carcinoma Ceruminoma Cutaneous myoepithelioma Cylindroma Eccrine carcinoma Hidradenoma papilliferum Hidrocystoma Microcystic adnexal carcinoma Mucinous carcinoma Papillary eccrine adenoma Poroma Porocarcinoma Syringadenoma papilliferum Syringofibroadenoma Syringoma Adenolipomas are lipomas associated with eccrine sweat glands. As signs in other illnesses Many diseases cause sweat gland dysfunction: Acromegaly, a result of excess growth hormone, causes the size of sweat glands increase, which leads to thicker skin. Aquagenic wrinkling of the palms, in which white papules develop on the palms after exposure to water, can sometimes come with abnormal aquaporin 5 in the sweat glands. Cystic fibrosis can be diagnosed by a sweat test, as the disease causes the sweat glands ducts to reabsorb less chloride, leading to higher concentrations of chloride