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Hyperhidrosis (Excessive Sweating)

What is Hyperhidrosis?

Hyperhidrosis refers to excessive sweating that goes beyond normal physiologic needs. Those with hyperhidrosis may sweat heavily even in cool temperatures or when inactive, which can lead to significant discomfort and impact to daily life. Excessive sweating affects around 3% of the Australian population.

The precise cause of primary hyperhidrosis is unknown, though it may involve overactivity of the sympathetic nervous system which controls sweating. Secondary hyperhidrosis can arise from an underlying condition like a hormone imbalance, cancer, or infection and requires diagnosis and treatment of the underlying cause.

Botulinum toxin, the same injection used to reduce wrinkles, was TGA-cleared in 2013 for severe underarm sweating when other treatments fail. Other treatments include oral medications, topical creams, prescription antiperspirants, or surgery.

What Are The Symptoms of Hyperhidrosis?

Patients with hyperhidrosis can experience a range of symptoms due to excessive, uncontrollable sweating, including:

  • Visible sweat marks on clothing (e.g., underarms, hands, feet) that can be embarrassing and require frequent changing of clothes. Excessive sweating can soak through clothing.
  • Slipping or dropping objects due to sweaty, slippery hands or feet. This can impact daily activities and be dangerous for tasks requiring grip.
  • Skin problems like infections or maceration from constant moisture against the skin. Commonly affected areas include underarms, hands, feet, and groin.
  • Anxiety or social discomfort due to visible/uncontrollable sweating. This can significantly impact the quality of life, relationships, and work or school activities.
  • Chills or feeling cold due to sweat rapidly cooling on the skin, even in a hot environment. This paradoxical cold sensation can make temperature regulation difficult.

Excessive sweating can be an embarrassing and debilitating condition. For those struggling with hyperhidrosis that does not respond to other treatments, botulinum toxin injections may provide relief. But how does injecting a neurotoxin lead to reduced sweating?

Botulinum toxin works by temporarily blocking the chemical signals from nerves that stimulate sweating. When injected into the skin, it binds to the nerves that activate sweat glands. It is absorbed into the nerve cells, where it then inhibits the release of acetylcholine, a neurotransmitter that triggers sweat production. By blocking this signal, it essentially turns off sweating in the area where it’s injected.

Ideal candidates for botulinum toxin injections are those with primary focal hyperhidrosis, where excessive sweating is localized to specific areas such as the underarms, palms, soles, or face. Candidates should have not responded sufficiently to other treatments like clinical antiperspirants, iontophoresis, or oral medications.

To qualify for a PBS-subsidized treatment of severe primary axillary hyperhidrosis, the following criteria must be met:

  • The patient must have either failed topical aluminum chloride hexahydrate treatment after 1-2 months, or be intolerant of such treatment.
  • The patient must be at least 12 years of age.
  • The treatment must be administered by either a dermatologist, neurologist, or pediatrician.
  • The patient may receive up to 3 treatments per year, with at least 4 months between each treatment.
  • Botulinum toxin injections are given using a fine needle, directly into the affected sweat glands. The procedure is typically quick, around 10-30 minutes, and no anesthesia is required. Patients can resume normal activities right away.


    Botox injections can significantly reduce excessive sweating in the treated areas. The effects are not immediate – it can take around 1-2 weeks for the full results to kick in. The treated areas will sweat less, and sweating may be stopped entirely in some cases. The results are temporary, lasting 3-4 months on average, before the effects fade and repeat injections are needed.

    Studies have found that botulinum toxin can decrease underarm sweating by 82-87% in those with severe armpit sweating. Repeat injections tend to increase the duration of efficacy of botulinum toxin, lasting for more than 20 months in some cases.

Book an appointment

Melbourne NeuroCare offers botulinum toxin injections to effectively reduce excessive sweating. If you suffer from primary focal hyperhidrosis – excessive underarm, palm, sole or facial sweating – botulinum toxin injections can provide substantial relief. In a quick, minimally invasive procedure, the toxin is injected directly into your sweat glands to reduce sweat production. Many patients get 4 to 12+ months of significant sweat reduction from a single treatment. Schedule an appointment now.