A medical condition known as hyperhidrosis, which causes excessive sweating, affects approximately 1-3% of people in the UK. This condition can amplify sweating in stressful situations, as observed by TV comedian Alan Carr, who has spoken about his "sweating problem" when selected as a celebrity traitor.
Sweating occurs for two main reasons: when the body overheats or due to emotional responses like anxiety, fear, pain, or stress. The body's eccrine sweat glands, which make up about 90% of all sweat glands, are activated by a neurotransmitter called acetylcholine, playing a central role in involuntary actions such as sweating. In high-stress situations, adrenaline can also activate these glands, leading to sweating across the body.
Individuals with hyperhidrosis can sweat at rates significantly higher than what is considered normal, potentially losing up to 5.8 litres of fluid per hour. This increased fluid loss puts them at a greater risk of dehydration. Additionally, the warm, moist skin environment created by excessive sweating can increase the risk of fungal infections, such as athlete's foot, and bacterial infections, like impetigo, as well as body odour.
The cause of primary hyperhidrosis, which accounts for 93% of cases, is unknown, though genetic factors are thought to play a role. Treatments for hyperhidrosis range from prescription antiperspirants for mild to moderate cases, to iontophoresis, and botulinum toxin injections for more severe instances. These injections block the action of acetylcholine, reducing sweat gland activity, with effects typically lasting around six months.