By the term hyperhidrosis (from Greek ὑπέρ (hypér) “even more, over, beyond … beyond” and ἱδρώς (hidrós) “sweat”; synonyms: Hyperhidrosis; pathologically increased perspiration; night sweats; sweating; tendency to sweat; increase in sweat secretion; excessive sweating; excessive night sweating; ICD-10-GM R61.-: Hyperhidrosis; incl.: Night sweats: excessive sweating) refers to an unphysiologically strong sweating. Sweating is a vital process of the human body to protect the body from overheating (thermoregulation). Basically, there are two types of sweating:
- Thermoregulatory sweating (regulated by the hypothalamus (part of the diencephalon)).
- Emotionally conditioned sweating (regulated by the limbic system (functional unit of the brain that serves the processing of emotions and the emergence of drive behavior)).
The skin has a total of more than 2 million sweat glands. The majority of sweat glands are of the eccrine type (secreting outward). Their thin secretion is hypotonic compared to blood plasma (protein-rich fluid). The eccrine sweat glands are distributed over the entire body. The highest density is found in the axillae, palms and soles of the feet.In addition, there are apocrine sweat glands, which have the property of secreting their secretion together with the apical part of their cytoplasm and parts of the cell membrane. Apocrine sweat glands are located in the axillary and urogenital regions. They secrete odoriferous substances, which, together with the sebaceous glands, are largely responsible for body odor (sometimes unpleasant odor; see bromhidrosis below) and play a role in sexual behavior.Hyperhidrosis is divided into:
- Primary (idiopathic) hyperhidrosis – increased sweating in which no disease is present; occurs most commonly focally in circumscribed areas of the body, but may also be generalized, that is, over the entire body; predilection sites (areas of the body where the condition occurs preferentially): armpits, palms, soles, and forehead.
- Secondary hyperhidrosis (occurs due to disorders of the central or peripheral nervous system) – increased sweating due to a disease; this includes night sweats; usually occurs generalized.
A special form of hyperhidrosis is bromhidrosis (Greek βρῶμος (brômos) ‘goat stench of animals’; ἱδρώς (hidrós) or osmidrosis (ancient Greek ὀσμή osmē “I smell“)). This is excessive sweating and an unpleasant odor, which is a great distress to the sufferer. This usually occurs in the axillary region because the occurrence of apocrine scent glands is particularly high there. Primary (idiopathic) hyperhidrosis already appears in childhood or adolescence (< 25 years of age). Increased night sweating is a symptom that often occurs in infectious diseases, but also in tumor diseases (cancer). A combination of increased night sweats, weight loss, and fever is called B-symptomatology. Sweating can be a symptom of many diseases (see under “Differential diagnoses”). The prevalence (disease incidence) of primary focal hyperhidrosis (PFH) is 1% (in the UK). Course and prognosis: Frequent and excessive sweating interferes with daily life. Many affected individuals withdraw from their social environment out of shame. Normally, in many cases, self-measures against sweating such as appropriate personal hygiene (disinfectant soaps or deodorants), use of an antiperspirant (powders, creams, solutions) and adequate clothing (e.g. no synthetic clothing) are sufficient. If these measures do not help sufficiently, a doctor should be consulted for further advice.In the case of acute sweating accompanied by cold sweat all over the body, a doctor should be consulted immediately, as this may hide a myocardial infarction (heart attack).
