Let’s Talk About Armpit Pain—Is It Normal or a Sign of Something Serious?

Armpits may not seem the most glamorous topic, but armpit pain could indicate a health problem, especially if the pain seems to come out of nowhere. Here are some of the many common causes of armpit pain:

Infected or inflamed lymph node: Especially if your armpit pain is accompanied by a small lump. “Your lymph nodes are located underneath your arms and in your neck, and when they become infected or inflamed, they can become large, painful, and tender to the touch,” says Jeremy Allen, MD, with American Family Care (AFC), who serves as the medical director for AFC’s Birmingham, Alabama region. “Their location make lymph nodes hard to ignore when they begin presenting problems. They are typically associated with a larger fungal, bacterial, or viral infection in the body.” Although far less common, some lymph node swelling can be a sign of certain types of cancer, so a visit to the doctor is always recommended for a situation like this.

Allergies: A rash or burning sensation in your armpit could be caused by a skin allergy. Common irritants include soaps, deodorants, antiperspirants, and clothing materials. Your doctor can detect the cause of the rash by doing an allergy test on your arm. “There are, thankfully, many alternative formulas for soaps, deodorants, and antiperspirants that have ingredients your skin might tolerate better,” says Dr. Allen.

Infected sweat glands or hair follicles: “If you find lumps, red splotches, and itchy spots, your painful armpits might be the result of infected sweat glands or hair follicles,” says Dr. Allen. Causes include poor hygiene, prolonged periods of warm, moist conditions under your arms, and excessive sweating. You can help prevent this form of irritation by always showering or at least changing clothing after a sweat session. “If an infection occurs, try to wear very loose-fitting and airy clothing to let the armpits get some ventilation, and thoroughly wash the affected area to rid it of bacteria, dead skin, and excess skin oils,” Dr. Allen says.

Pulled muscles: Severe armpit pain can be caused by pulled or strained pectoral, triceps, or latissimus dorsi muscles. While there are no specific muscles in the armpit itself, pain from surrounding muscles can travel to this area, according to Dr. Allen. Time and rest will alleviate the pain, and you can take ibuprofen for relief in the meantime. (Here are other common causes of latissimus dorsi pain.)

Menstrual pain: The tissue of the breasts reaches into the armpits. If your breasts get sensitive during your menstrual cycle, it can affect the armpits, too.

Razor burn: Shaving is another reason you might be experiencing armpit discomfort. Razor burn occurs when the skin is not properly lubricated during shaving. “Your armpits are especially vulnerable to razor burn because they are uneven surfaces with some loose skin and ridges that make it difficult to adequately distribute conditioner/cream and apply even pressure with a razor,” says Allen. If you do get razor burn, be sure to keep the skin clear, and avoid shaving again until the area has healed. Here are common ways you could be shaving wrong, and how to do it properly to avoid nicks, cuts, and razor burn.