Underarm sweating
Axillary hyperhidrosis
The one form of excessive sweating Medicare subsidises — and the one that responds most reliably to treatment.
Can this be treated?
The 20-second answerYes, and this is the sweating I can help with most. Anti-sweat injections settle underarm sweating in over 96% of people, take effect in 7 to 10 days, and last six to eight months once you have had a few. The first course usually runs shorter — four to seven months — and lengthens with subsequent treatments.
The underarm is the only site where a Medicare rebate applies, and it is why underarm treatment costs a fraction of what the same injections cost anywhere else on the body.
The treatment is $890. Medicare item 18362 carries a schedule fee of $295.30 and pays an out-of-hospital benefit of $251.05, which leaves you $638.95 out of pocket per treatment. If you have reached the Medicare Safety Net for the year your benefit is higher and your gap smaller.
To claim it you need to meet the criteria: severe primary axillary hyperhidrosis, a clinical-strength aluminium chloride antiperspirant properly trialled and failed, and no anti-sweat injections in the preceding four months. Three treatments per calendar year is the maximum, at least four months apart. A GP referral is not required.
Medicare figures are the schedule as at 1 July 2026 and are reviewed annually.
What it is not is permanent. This is control, repeated a few times a year, not a cure.
Is this you?
Recognising the patternPrimary focal hyperhidrosis has a recognisable pattern. If most of these are true, that is almost certainly what you have.
- Both underarms, roughly evenly — not one side only
- It stops while you are asleep, and starts again when you wake
- It has been going on for more than six months
- It happens at least twice a week
- It started in childhood, adolescence or your twenties
- Someone else in your family sweats like this
Sweating on one side only, sweating that wakes you at night, or sweating that started suddenly in adulthood points somewhere else — thyroid, medication, infection or something systemic. That needs a GP or a physician before it needs me.
How severe is it?
The scale I actually useThis is the Hyperhidrosis Disease Severity Scale — the same four-line scale used in the research and, for underarm treatment, in deciding whether you qualify for a rebate. Pick the line that fits.
What causes it
Why this happens to you and not your brotherPrimary hyperhidrosis is a wiring problem, not a gland problem. The sweat glands are normal; the nerve signal telling them to fire is set too high. It is genetic — the International Hyperhidrosis Society finds around 18% of sufferers have an immediate family member with it, and studies of surgical patients put family history as high as 35 to 56%.
Stress, caffeine and some medications make it worse. None of them cause it. You did not bring this on yourself, and no amount of showering changes it.
Your options, in order
What is available, and how well each works| Option | How it works | How well | How long | Cost |
|---|---|---|---|---|
| Clinical-strength antiperspirant | Aluminium chloride hexahydrate plugs the duct. Applied at night to dry skin. | Works for mild cases | Nightly, then twice weekly | ~$15 a month |
| Anti-sweat injections | Anti-sweat injections, placed just under the skin across the sweating area. Blocks the nerve signal to the gland. | Over 96% | 6–8 months | $160–$590 out of pocket |
| Anticholinergic tablets | Prescription tablets from your GP. They reduce sweating everywhere, not just the underarm. | Modest | While taking them | Prescription |
| miraDry | Microwave energy that destroys sweat glands permanently. | Up to 80% | Permanent | Two sessions, 12 weeks apart |
| ETS surgery | Keyhole surgery dividing the sympathetic nerve chain. | Very high | Permanent | Last resort — see below |
What treatment actually involves
Start to finish- First
Trial a clinical-strength antiperspirant containing aluminium chloride hexahydrate. This is not a formality — Medicare requires that you have tried and failed it before the rebate applies. It is available over the counter.
- Assessment
A consultation to confirm this is primary axillary hyperhidrosis and not something else. A starch-iodine test can map the exact area, though it is rarely necessary.
- The injection
Under three minutes. Multiple small injections across each underarm, just under the skin. Most people describe it as an ant bite. No anaesthetic, no downtime, back to work immediately.
- 7 to 10 days
Sweating reduces, then stops. Not instant — the effect builds over the first week and a half.
- 6 to 8 months
The effect wears off gradually. You will know when it is time. Medicare allows three treatments per calendar year, at least four months apart.
Realistic results
Including what will not changeThe honest numbers. Over 96% of people get a good result — this is one of the most reliable treatments in dermatology, and considerably more predictable than most cosmetic procedures.
On the severity scale used to assess this, a one-point improvement is roughly a 50% reduction in sweat production and a two-point improvement roughly 80%. Most patients move from a 4 to a 1.
What will not change: body odour is a separate problem with a separate cause, and treating sweat only partly helps it. Sweating elsewhere is unaffected — treating the underarms does not push sweat to your hands or face, which is a common and unfounded worry. That phenomenon, compensatory sweating, follows surgery, not injections.
Cost and Medicare
Underarm hyperhidrosis is the only site with a Medicare rebate, under item 18362. Depending on your Medicare status, expect $160 to $590 out of pocket per treatment.
To qualify you must be at least 12 years old, have tried and failed topical aluminium chloride hexahydrate, and have had no anti-sweat injections in the preceding four months. Three treatments per calendar year is the maximum, at least four months apart. A GP referral is not required to claim the rebate.
One practice note: although the Medicare item begins at 12, I see patients from 13. A younger child is better served by a paediatric dermatologist.
Downtime and side effects
None. You walk out and carry on with your day. Small red marks at the injection sites settle within an hour.
Bruising is possible and uncommon. Some people notice a mild ache in the underarm for a day. Sweating carries on normally until it starts to reduce at day seven — do not assume it has failed before then.
What I would be cautious about
The honest counterweightmiraDry. It is permanent, and it does reduce sweating by up to 80%. But your underarm will be red, inflamed and swollen for four to ten days, it usually needs repeating at twelve weeks, and in my view the side effects are under-reported — it causes significant nerve pain in a proportion of patients. I would exhaust injections first.
ETS surgery. Very effective and irreversible. Compensatory sweating — the body sweating heavily somewhere else instead, usually the trunk — follows in a large minority of patients and cannot be undone. For underarms alone, it is almost never the right trade.
Common questions
Does it hurt?
How soon does it work?
Will the sweat go somewhere else?
Can I have the rest injected into my face?
Do I need a GP referral?
What if antiperspirant works for me?
How often can I have it?
Where to from here
A virtual consultation gives you a written plan for your case — which option, in what order, what it will cost and what it will not fix — before we speak.
Clinical content from Dr Lim’s published pages. Epidemiology and the severity scale from the International Hyperhidrosis Society. Rebate criteria from MBS item 18362. General information only — it is not a substitute for assessment.
See the work before you book
Procedures, technique, before and afters, and the reasoning behind them — posted across three accounts, each with its own focus.
Have some questions?
Send a message and it will be answered personally. Form endpoint — to be wired in production