Many people with breast cancer undergo a lymph node removal near the armpit as part of their treatment. Following this surgery, some MyBCTeam members have pointed out new and unusual changes in their bodily functions. “One armpit is stinky, and the other one is not even wet!” one MyBCTeam member noted.

In this article, we will address how breast cancer treatments might change the way you sweat, explore how members of the MyBCTeam community describe this feeling, and offer practical tips for managing this new symptom.

Members Describe Changes After Lymph Node Dissection

Noticing a difference in everyday bodily functions after treatment can be alarming. “I had an odd odor on that side for a couple of months, and even asked my surgeon about it,” wrote one MyBCTeam member who dealt with excessive sweating on the armpit that didn’t have surgery. “After a while (maybe three months), it went away and the glands worked normally.”

“I have noticed that I don’t sweat from my armpit on the affected side,” one member said. “My sweating is localized to the side where I didn’t get surgery.”

Not only do members discuss changes in their sweat, but also in hair growth. “I had five lymph nodes removed from my right armpit, and now I haven’t had the need for deodorant or shaving,” another member shared. “I just can’t forget to shave my hairy left armpit — now that would be embarrassing.”

Based on these and other MyBCTeam members’ experiences, it’s not uncommon to deal with one-sided sweating, odor, or hair growth after lymph node removal from one armpit. What could cause this phenomenon?

Reasons for One-Sided Sweat Changes

Whether you’re experiencing more or less sweat on the affected armpit, there may be some reasons behind the changes.

Lymph Node Dissection

Common side effects after a lymph node removal may include swelling, stiffness, and scarring. Many people who’ve undergone this procedure have also reported a reduction in sweating on one side .

In one study of 65 people who underwent this lymph node sampling or clearance, 29 reported that they experienced reduced underarm sweating. The reasons for this symptom have not been well studied, but may be related to damage of the nerves in your underarm that stimulate your glands to produce sweat.

Other Breast Cancer Treatment

Nonsurgical breast cancer treatment, such as radiation, chemotherapy, and hormonal treatment, can also change the way you sweat. People who have undergone these treatments may experience hot flashes and night sweats, which may increase the amount of sweat in one or both armpits. In combination with lymph node removal in one armpit, the way you experience sweat and odor may vary drastically after your treatment has ended.

Some methods of breast cancer surgery can also lead to changes in armpit sweat and odor. “I had a double mastectomy, and since then I have not had any underarm odor,” one MyBCTeam member wrote.

Other Causes

Besides the natural changes in your sweating function from breast cancer treatment, other conditions can also cause one-sided sweating. If you suddenly start sweating on only one side of your body without any other explanation, it may be a condition called asymmetric hyperhidrosis. This can be caused by a nerve issue or a skin infection. See your doctor right away if you experience severe one-sided sweating accompanied by dizziness, nausea, clammy skin, or seizures.

Managing One-Sided Sweat Changes

What can you do about one-sided underarm changes? Many MyBCTeam members have chosen to look at the bright side of unilateral sweating. “I am kind of happy with not having to shave or use antiperspirant under the affected arm,” one shared.

Sweat, smells, and hair growth are all natural functions of armpits. While breast cancer treatment may increase, reduce, or stop sweating on one side, the other armpit may still operate as it always did. Options for preventing or managing excess sweating include:

• Antiperspirants — Contrary to popular belief, there is no scientific evidence to say that antiperspirants can increase the risk for breast cancer. Therefore, they should be safe to use if you are experiencing excess sweating on one side.
• Prescription wipes — Wipes that contain glycopyrronium tosylate, prescribed by a doctor, are effective in reducing the amount of sweat your armpit produces.
• Deodorant — While deodorant does not stop you from sweating, it does reduce the smells that are associated with your sweat.
• Dermatology procedures — Different types of surgery or injected medications, such as botulinum toxin (Botox), can help reduce the amount of sweat that your skin produces. Speak to your doctor if excessive armpit sweating is disrupting your quality of life.

Speak to Your Doctor

Experiencing odd symptoms after lymph node dissection, or other forms of breast cancer treatment, is common. Your symptoms may be different from other people’s, making it hard to know what symptoms to expect after treatment. “Nice if someone would have told us, huh?” one member said.

While it may feel embarrassing to bring this symptom up to your doctor, remember that many others have experienced this same treatment complication. If your one-sided sweating is bothering you or if you also have symptoms such as swelling or pain, speak with your oncologist or breast surgeon for medical advice.

Talk With Others Who Understand

On MyBCTeam, the social network for people with breast cancer and their loved ones, more than 64,000 members come together to ask questions, give advice, and share their experiences with others who understand life with breast cancer.

Have you experienced changes in sweating after a lymph node removal? What tips do you have for others recovering from this procedure? Share your experience in the comments below or join the conversation on MyBCTeam.