A lump in you armpit doesn’t necessarily mean cancer, because it more likely has a benign cause.

Have you recently discovered a lump in your armpit and immediately thought, “It’s cancer!”?

Relax, because chances are in your favor that the lump under your arm does not have a life-threatening cause.

It’s just that the discovery of a lump — whether visible or only detectable with probing fingers — is one of the warning signs that we’ve all learned can be caused by many different cancers.

Cancers that are infamous for causing lumps that are first detected by the patient include that of the breast, prostate, testicles, lymph nodes, bone and inside the mouth.

Origin of Most Underarm Lumps

“In general, armpit lumps are from lymph glands or sweat glands,” says Dr. Steven Lamm, MD of internal medicine, who appears regularly as the house doctor on ABC’s “The View,” and author of “No Guts, No Glory,” a book about digestive issues.

Dr. Lamm continues, “Lymph glands can swell from infections anywhere in the arm or from a generalized infection.

“Sweat glands, also, can get blocked and swollen. The most common condition is called hidradenitis.”

Hidradenitis suppurativa is a chronic skin inflammatory condition that can last for years, characterized by blackheads and at least one tender bump that can get bigger, break open and ooze pus.

The armpits and groin are common locations.

Finally, a cause of a “lump” under the arm can simply be your natural lymph node.

Some years ago while performing a self-breast exam I found a lump under my arm, and could not locate a mirror image of it on the other side—initially, that is.

Eventually I was able to feel around my other armpit and locate a similar lump in the same relative location.

Variations in sinew and muscle can account for why, on one side, there seems to be a “lump,” while on the other side, there’s none there.

On the clinical faculty in internal medicine at New York University Medical Center, Dr. Lamm has maintained a private practice in NYC for 30+ years.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: Freepik.com, valuavitaly