Hyperhidrosis is a very common condition in which an individual sweats excessively. This sweating can affect your whole body or it can affect just certain areas of your body. The most common affected areas are:
- Face and chest
- Soles of your feet
- Palms of your hand
Both sides of your body are usually affected equally, for example both hands or the both feet are affected. The excessive sweating is not usually a serious problem for your health but it can be very distressing and embarrassing condition. Also it can have negative impact on the quality of your life and this can lead to feelings of anxiety and depression. [1,2]
Causes of hyperhidrosis
This condition can be divided into 2 types which depend on whether an obvious cause can be identified. There are known as primary and secondary hyperhidrosis.
- Primary hyperhidrosis: Hyperhidrosis in which there is not an obvious cause for it is known as primary hyperhidrosis. Although is not clear why this type of hyperhidrosis develops, it is thought that it is a result of a problem with part of our nervous system which is called the sympathetic nervous system and also it is possible that your genes can play a role in it.
- The sympathetic nervous system: This part of our nervous system controls most of our body’s functions which do not require conscious thoughts such as the movement of urine out of your kidneys and into bladder and the movement of food through your body. This part of the nervous system also acts like a thermostat. If it senses that you are getting too hot, then it will send a signal from the brain to the sweat glands (there are millions of sweat glands) in the body to produce the sweat. This sweat will cool on your skin and it can reduce the temperature of your body. The eccrine glands, which are a specific type of sweat glands, appear to be involved in the hyperhidrosis. There are more eccrien glands on the face, feet, hands and arms which are explaining us why these areas are most commonly affected by hyperhidrosis. Also it is though that in the case of primary hyperhidrosis, our brain sends signals to the eccrine glands, even though there is no need to cool our body. 
- Genes: There are some cases when the primary hyperhidrosis can appear to run in the families which mean that there is a genetic mutation that is the cause for the primary. A genetic mutation is where the instruction in our cells become scrambled which can disrupt the normal working of our bodies. There are some genetic mutations which can be passed down from parents to children. 
- Secondary hyperhidrosis: Secondary hyperhidrosis is when the cause of hyperhidrosis can be identified. Secondary often starts suddenly than the primary hyperhidrosis and it tends to affect your whole body. This type of hyperhidrosis can have many different triggers such as:
- Disorders of the blood cells or bone marrow, such as Hodgkin lymphoma (a cancer of the white blood cells)
- Parkinson’s disease
- Some infections, such as HIV and tuberculosis
- Being drunk or “high” on drugs, or withdrawing from alcohol or drugs if you have become addicted to them
- Certain medications – including some bethanechol, pilocarpine, propanolol and antidepressants
- Obesity 
- An overactive thyroid gland (hyperthyroidism)
- Low blood sugar (hypoglycaemia)
- Anxiety [2,3]
- The menopause – when the monthly period of woman stops
This condition does not usually pose a serious threat to your health but there are some cases when it can lead to emotional and physical problems.
- Fungal infections: This condition can increase the risk of fungal infections which appear on the feet such as Athlete’s foot and fungal nail infections. 
- Skin conditions: Excessive sweat can make you more vulnerable to some skin conditions  such as:
- Emotional impact: People who live with hyperhidrosis can have emotional impact. There are many people who feel unhappy and in some cases they can be depressed. [1,2,3] Signs that you may be depressed include:
- Having little interest or pleasure in things during the past month
- Feeling down, depressed or hopeless during the past month
 Kamudoni P, Mueller B, Halford J, et al. The impact of hyperhidrosis on patients’ daily life and quality of life: a qualitative investigation. Health and Quality of Life Outcomes. 2017.
 Klein SZ, Hull M, Gillard KK, Peterson-Brandt J. Treatment patterns, depression, and anxiety among US patients diagnosed with hyperhidrosis: A retrospective cohort study. Dermatology and Therapy. 2020;10:1299–314.
 Schlereth T, Dieterich M, Birklein F. Hyperhidrosis – Causes and treatment of enhanced sweating. Deutsches Ärzteblatt International. 2009;106(3):32–7. doi:10.3238/arztebl.2009.0032
 Ro KM, Cantor RM, Lange KL, Ahn SS. Palmar hyperhidrosis: Evidence of genetic transmission. Journal of Vascular Surgery. 2002;35(2):382-6.
 Astman N, Friedberg I, Wikstrom JD, et al. The association between obesity and hyperhidrosis: A nationwide, cross-sectional study of 2.77 million Israeli adolescents. Journal of the American Academy of Dermatology. 2019;81(2):624-7. doi:10.1016/j.jaad.2019.01.019.
 American Academy of Dermatology. Patients with excessive sweating condition are more likely to develop skin infections. Science Daily. 2009. Retrieved from www.sciencedaily.com/releases/2009/05/090507181418.htm