Lump in the armpit: questions about an armpit bump or thickening

Feeling a lump in the armpit or under the arm is often a bit of a shock. When they see a skin lump, many people immediately think of cancer. But the cause of a lump under the arm is not always so serious. It is often a thickened gland in response to inflammation. The lymph nodes can then swell and later return to their normal size on their own. However, no cause should be ruled out for a lump in the armpit, especially when additional symptoms are observed, such as fever or pain in the armpit lump. Cancer can also be a possible culprit of a lump in the armpit. How seriously should you take an armpit bump and what can you do about it? Asking a doctor a few questions can help to make an initial assessment of the potentially problematic nature of a bump under the arm.

Armpit lump

If you feel something unusual in the armpit, it could be a lump or a thickening , for example . This lump is a kind of lump that settles in the armpit and can possibly cause pain. The medical examination will determine whether the lump is a symptom of a serious problem or is temporary. However, you can use certain criteria to determine how seriously you should take the lump under your arm.

Causes of a bump under the arm

In most cases, a thickening under the armpit is a sign of an innocent problem. Our body has many glands and these are very concentrated in some places. Examples of these places are the neck, sternum, abdomen and armpit. The lymph nodes in the body ensure the removal of waste products from the body. If one of those lymph nodes is clogged, this in most cases indicates that the bacteria are processing an inflammation . A thickening or swollen spot under the armpit can also be the result of an allergic reaction.

Lymph nodes in “overdrive”

Swollen glands

Your lymph nodes contain white blood cells that are fully active in the processing of waste products. During this activity, the white blood cells will swell, which also causes the gland to thicken and you will notice the entire process in the form of a bump. The bump may be the size of a pea and may be tender or painful.


But in this case, a thickening under the armpit is a sign that your glands are working hard to recover from an inflammation or allergic reaction. You can say that they are in “overdrive” to heal your body of the unnecessary waste. The glands are therefore very active in the healing process of the body.

Disappearance of armpit lump

In most cases, the armpit lump will disappear on its own when the white blood cells in the lymph node have completely processed the waste products. This may take a few days or weeks, but it is generally assumed that you should get rid of it after four weeks. If you still have a lump under the armpit after four weeks, it is best to consult a doctor to be sure.

Questions about armpit thickening

In the case of a bump under the armpit, the doctor will first check a number of factors that should provide him with important information, such as:

  • Does the lump hurt?
  • How long have you had the lump?
  • Does the lump feel very hard?
  • Has the lump become smaller or larger?
  • Are there any symptoms that have occurred since the armpit bump appeared?

Additional symptoms

Based on the answers to these questions, the doctor will get a good idea of the seriousness of the situation. The longer the lump is present, the greater the chance of a more serious condition. The same applies to additional symptoms that may indicate a deeper cause :

  • fever
  • listlessness
  • rapid fatigue
  • noticeable weight loss

Armpit lump and cancer


Cancer is often the first thing a person thinks of when they suddenly notice a lump or bump under the arm or in the armpit. A hard-feeling, rapidly growing bump may be related to a tumor. However, cancer is quite rare as a cause of an armpit bump and in most cases the thickening will disappear over time.


But if serious symptoms occur, it is certainly recommended to think of all possibilities. Specific research will be able to show whether there are indications of cancer or not. The doctor will usually examine the swollen glands near the site and may also perform an extensive scan to see if there are any cancerous growths (e.g. breast cancer). A biopsy can also be performed in which tissue is removed and examined in the medical laboratory.

Armpit bump treatment

Pain relieving gel

If you are bothered by the bump under the armpit, you can apply a soothing skin cream or gel locally. This can be a cream or gel for sensitive skin, or a gel that has both an analgesic and anti-inflammatory effect. The advantage of a gel or cream is that it acts very locally on the affected area and that you can see results relatively quickly.
Some examples of gels that have an analgesic and anti-inflammatory effect:

  • Pro Fit Ibuprofen Gel
  • Voltaren Emulgel (diclofenac)


In addition to a gel or cream that soothes the pain, you can also opt for a classic painkiller to ease the pain and discomfort. If the bump is painful and sensitive, a painkiller can help you sleep better at night. If these treatment options do not provide relief and the lump appears to be persistent, consult a doctor.
Some examples of painkillers:

  • Final
  • Nurofen
  • Paracetamol


If the armpit lump is serious and cancer is the cause of the problem, urgent medical treatment will be required. Chemotherapy, radiotherapy and surgical removal of the lump are among the treatment options.

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