Hyperhidrosis - Axillary

Sweat is a solution of water and salts produced by glands immediately under the skin and cools the body by evaporation during exercise and in warm surroundings. The activity of these glands is normally controlled by the nervous system. In a small number of people (less than 1.0% of the population), this control mechanism fails to function normally causing excessive sweating, even when body temperature is normal. This condition is known as hyperhidrosis.

Occasionally, hyperhidrosis occurs as a result of abnormal hormone levels and these will be measured as part of the assessment of people with this condition. In most cases, no reason for the excessive sweating will be identified by these tests. 

Excess sweating may occur anywhere but usually affects the hands, armpits, scalp, face, and/or feet. Although some people may find this excess sweating embarrassing, it is not a dangerous or life threatening condition.


The principle means of treating this condition are the use of potent antiperspirants, surgery and Botulinum toxin injection (Fitzgerald et al. 2004 )


The most effective antiperspirant is Aluminum Chloride - typically Anhydrol Forte(TM) - which may be prescribed for you. This is applied in the evening 2-3 times per week and washed off the following morning. In some cases, it causes skin irritation. The treatment must be repeated regularly for life. This agent cannot be used on the face or scalp.

Botulinum toxin injection 

This treatment is suitable for people who find the topical antiperspirants ineffective or develop skin problems when using them. Its is a safe and effective treatment for underarm hyperhidrosis. This procedure is performed using local anaesthesia in the day ward or outpatient department. The evening before your procedure you should carefully shave your underarm area. Do not apply antiperspirants or deodorants. If you have been given a local anaesthetic preparation, apply this in the morning before you leave home to attend the clinic. Cover the local anaesthetic cream with an occlusive dressing (which was also supplied)  

On the morning of your procedure you will be asked to attend the OPD. If you have not been given a local anaesthetic cream to apply at home, local anaesthetic cream (Ametop) will be applied to the area and covered with an occlusive dressing.  The procedure only takes a few minutes and consists of a number (10-12) of tiny injections into the skin under each arm. These injections may cause minimal discomfort. The botulinum toxin binds to the nerve endings and prevents their effects on the sweat glands.  

The injections may take several days to work. During this time you should not shave but may use antiperspirants or deodorants. The nerve endings begin to regrow 6 to 9 months after the injections and you may notice recurrence of the sweating. You may be booked for a repeat treatment before you leave the clinic or an appointment will be sent out to you in the post. Please contact the Vascular Surgery office (in writing or by email - see the about us section) if you wish to have the injections repeated at this time.


While allergic reactions can occur, these are not common. There is a theoretical risk of developing botulism from botulinum toxin injections. This is a very serious illness that can be life threatening but this has never been described with the preparation that we use in our clinic (Botox, Allergen).

Occasionally, the treatment is ineffective and must be repeated. 

It is possible that, over time, patients may develop antibodies to botulinum toxin which will prevent the treatment having any effect. 

However, in several studies in large numbers of patients, we have shown that Botulinum Toxin is a cost effective treatment over at least 5 years (Lynch et al 2020; Gibbons et al. 2016).


The surgical procedure used in the treatment of severe hyperhidrosis is called endoscopic thoracic sympathectomy (ETS) or TTEC (trans thoracic electrocoagulation )

Surgery may be considered in those who find the botulinum toxin treatment ineffective. However, complications are common and this procedure is now rarely used for the treatment of axillary hyperhidrosis.

During the procedure, the nerves that supply the sweat glands in the hands and axilla (armpit) are permanently divided within the chest cavity. Patients are admitted as a day case. Under general anaesthesia, each lung is collapsed in turn. Through 5mm incisions in the chest wall, two or three incisions (5-10mm) are made in the skin under each arm. Ports are inserted through these incisions and using a small camera and the nerves are divided using electrocautery.


Although this is a safe procedure in most patients, complications can occur in a small number of people. While the axilla and the arm will be dry, compensatory increase in sweating from other parts of the body (compensatory hyperhidrosis) may be quite troublesome. This occurs in up to 50% of patients and is troublesome in up to 20%.

In addition, if the branches of the nerves that supply the face are damaged during the operation, this may cause visible drooping of the eyelid (Horner’s syndrome). While uncommon (<1%), this may be permanent.   

Occasionally, the lung may fail to reinflate and it may be necessary to place a small drainage tube into the chest for a short time after the surgery. As with any surgery, bleeding or infection may occur but this is not common.

Injury to the nerves along the ribs may cause pain which may be persistent or even permanent.   

The heart and major vessels are close by and if these are injured, which occurs rarely, your life may be at risk.

Postoperative instructions 

After the procedure, you may have some mild discomfort. Some people may have pain (or altered sensation - numbness or tenderness) along the line of one or more ribs due to bruising of the nerves. While this will usually settle, it may persist for months in some cases or even be permanent. Dissolving stitches are usually used to close the wounds so there are no stitches to be removed. You may need to take some simple pain killers following the procedure which will be prescribed for you before you leave.  


Fitzgerald E, Feeley TM, Tierney S. Current treatments for axillary hyperhidrosis. Surgeon. 2004;2(6):311-360. doi:10.1016/s1479-666x(04)80028-3

Gibbons JP, Nugent E, O'Donohoe N, et al. Experience with botulinum toxin therapy for axillary hyperhidrosis and comparison to modelled data for endoscopic thoracic sympathectomy - A quality of life and cost effectiveness analysis. Surgeon. 2016;14(5):260-264. doi:10.1016/j.surge.2015.05.002

Lynch OE, Aherne T, Gibbons J, et al. Five-year follow-up of patients treated with intra-dermal botulinum toxin for axillary hyperhidrosis [published online ahead of print, 2020 Jan 3]. Ir J Med Sci. 2020;10.1007/s11845-019-02131-3. doi:10.1007/s11845-019-02131-3)