Excessive sweating (Hyperhidrosis)
Created: 09.01.2025
Updated 13.10.2026
Approved by: Consultant Dermatologist, Dr James Denny
What is Hyperhidrosis?
Hyperhidrosis is a condition that causes people to sweat excessively, often far more than is needed to regulate body temperature. While sweating is a normal and essential function that helps cool the body, people with hyperhidrosis produce sweat even when they are resting or in cool environments.
The condition affects up to 3% of the population and can have a significant impact on daily life, affecting work, social interactions, and self-confidence.
There are two main types of sweat glands in the skin:
- Eccrine sweat glands, which are found over most of the body and regulate body temperature by producing sweat.
- Apocrine sweat glands, which are mainly located in the armpits and groin and are responsible for body odour rather than temperature control.
Hyperhidrosis primarily involves overactivity of the eccrine sweat glands.
Types of hyperhidrosis
Hyperhidrosis is broadly divided into two forms.
Primary hyperhidrosis
Primary hyperhidrosis, also known as primary focal hyperhidrosis, is the most common form. It develops without an underlying medical cause and usually begins during childhood or adolescence.
It most commonly affects specific parts of the body, including:
- Underarms
- Palms of the hands
- Soles of the feet
- Face
- Scalp
Because sweating is limited to particular areas, this is also referred to as focal hyperhidrosis.
Primary hyperhidrosis usually affects both sides of the body equally and often has a family history.
Secondary hyperhidrosis
Secondary hyperhidrosis occurs as a result of another medical condition or as a side effect of medication.
Unlike primary hyperhidrosis, it often causes more widespread sweating and may occur during sleep.
Potential causes include:
- Hormonal disorders
- Diabetes
- Thyroid disease
- Certain infections
- Some medications
- Neurological conditions
If excessive sweating develops suddenly or is accompanied by other symptoms, further medical assessment is important.
What are the symptoms?
The main symptom of hyperhidrosis is uncontrollable sweating that exceeds what is needed for normal temperature regulation.
Symptoms may include:
- Sweat dripping from the hands or face
- Constantly damp palms or soles
- Sweat-soaked clothing
- Visible sweat marks
- Difficulty gripping objects
- Frequent need to change clothing
Primary focal hyperhidrosis usually affects both sides of the body symmetrically.
Many people also experience embarrassment, reduced confidence, anxiety, or limitations in work and social activities because of persistent sweating.
Night sweats
Hyperhidrosis that occurs only during the day is usually different from night sweats.
Night sweats are episodes of excessive sweating during sleep and may be associated with infections, hormonal changes, certain medications, or other medical conditions.
If you regularly experience unexplained night sweats, particularly when accompanied by weight loss, fever, or feeling generally unwell, medical assessment is recommended to identify any underlying cause.
How is hyperhidrosis diagnosed?
A dermatologist can usually diagnose hyperhidrosis based on your symptoms, medical history, and examination.
Your doctor will assess:
- Which areas are affected
- When the sweating occurs
- Whether sweating occurs during sleep
- Family history
- Any medications you take
- Symptoms suggesting an underlying medical condition
Blood tests or other investigations may be recommended if secondary hyperhidrosis is suspected.
What are the treatments?
Treatment aims to reduce excessive sweating, improve comfort, and minimise the impact on everyday life.
Clinical-strength antiperspirants
Prescription-strength antiperspirants containing aluminium chloride are often the first treatment for mild hyperhidrosis. They work by temporarily blocking sweat glands.
Oral medication
Anticholinergic medications, such as oxybutynin, reduce nerve signals that stimulate sweat production and may be appropriate for more widespread sweating.
Botox injections
Botulinum toxin (Botox) injections are an effective treatment for excessive sweating affecting the underarms, palms, soles, or forehead.
The treatment temporarily blocks the nerves that stimulate sweat glands, with results typically lasting several months before repeat treatment is required.
Iontophoresis
Iontophoresis uses a mild electrical current to reduce sweating in the hands and feet and is particularly useful for palmar and plantar hyperhidrosis.
Surgical treatment
For severe cases that have not responded to other therapies, surgical options such as endoscopic thoracic sympathectomy or removal of sweat glands may be considered.
These procedures are generally reserved for carefully selected patients because they carry potential risks and side effects.
Lifestyle measures
Although lifestyle changes cannot cure hyperhidrosis, they may help reduce symptoms.
Helpful measures include:
- Wearing loose, breathable clothing
- Using absorbent shoe inserts
- Avoiding known triggers where possible
- Carrying spare clothing when needed
- Maintaining good skin care to reduce irritation
A dermatologist can recommend the most appropriate treatment depending on the affected areas and the severity of symptoms.
What is the prognosis?
Hyperhidrosis is usually a long-term condition, but it can be managed successfully with appropriate treatment.
Many people experience significant improvement with medical therapies such as prescription antiperspirants, Botox injections, oral medication, or iontophoresis. Some individuals find that symptoms improve with age, while others require ongoing treatment to maintain symptom control.
Although hyperhidrosis is not dangerous, untreated excessive sweating can have a considerable impact on quality of life, affecting confidence, relationships, education, and work.
Early specialist assessment helps identify the type of hyperhidrosis and ensures that any underlying causes are recognised and treated appropriately.
Frequently Asked Questions
What is the difference between primary and secondary hyperhidrosis?
Primary hyperhidrosis develops without an underlying medical cause and usually affects specific areas such as the hands, feet, or underarms. Secondary hyperhidrosis results from another medical condition or medication and often causes more widespread sweating, including night sweats.
Why do I sweat excessively even when I'm not hot?
People with hyperhidrosis have overactive sweat glands that produce sweat even when body temperature is normal. The condition is caused by excessive stimulation of the nerves controlling sweating rather than overheating.
Can Botox stop excessive sweating?
Yes. Botox injections are a well-established treatment for excessive sweating of the underarms, hands, feet, and forehead. They temporarily block the nerve signals that activate sweat glands, with results typically lasting several months.
Are night sweats a sign of hyperhidrosis?
Not always. Night sweats are more commonly associated with secondary hyperhidrosis or another underlying medical condition. Persistent or unexplained night sweats should be assessed by a healthcare professional.
When should I see a dermatologist for hyperhidrosis?
You should seek specialist advice if excessive sweating affects your daily life, causes emotional distress, interferes with work or social activities, or develops suddenly without an obvious cause. A dermatologist can determine the type of hyperhidrosis and recommend the most appropriate treatment.
