Breast Lump: Causes, Symptoms & When to See a Doctor

What Is a Breast Lump?

A breast lump is any mass, swelling, or thickening in the breast tissue that feels different from the surrounding tissue. Breast lumps can be caused by many different conditions, ranging from harmless hormonal changes to breast cancer. Approximately 80% of breast lumps that are biopsied turn out to be benign (non-cancerous).

Breasts are composed of glandular tissue (milk-producing lobules and ducts), fatty tissue, and connective tissue. The relative proportions of these tissues vary from person to person and change throughout life, particularly during puberty, menstrual cycles, pregnancy, breastfeeding, and menopause. These changes are primarily driven by hormonal fluctuations, especially estrogen and progesterone.

Because breast tissue naturally varies in texture and density, many people notice areas that feel lumpy or different at various times. This is particularly common in the week before menstruation when hormones cause breast tissue to retain fluid and swell. Understanding what is normal for your breasts is an important part of breast health, as it helps you recognize genuine changes that warrant medical evaluation.

The discovery of a new breast lump can understandably cause significant anxiety. However, it is important to understand that the majority of breast lumps are not cancer. Many conditions can cause breast lumps, including fibroadenomas (the most common cause in younger women), breast cysts (fluid-filled sacs), fibrocystic changes, fat necrosis (damaged fatty tissue), and mastitis (breast infection). That said, because breast cancer is a possibility, all new breast lumps should be properly evaluated by a healthcare provider.

Breast tissue changes throughout life

Your breasts go through many normal changes during your lifetime that can affect how they feel. Understanding these changes can help you distinguish between normal variations and changes that need medical attention.

During puberty, breasts develop as the glandular tissue grows. This growth can sometimes be uneven, and it is common for one breast to develop faster than the other. Tenderness and lumpiness during this time are normal parts of breast development.

Throughout your menstrual years, hormonal fluctuations cause cyclical breast changes. Many people notice their breasts become fuller, more tender, and lumpier in the days before their period. These symptoms typically resolve once menstruation begins. Some areas of the breast may feel more nodular than others throughout the cycle - this is called fibrocystic change and is a normal variation.

During pregnancy and breastfeeding, the breast glands enlarge in preparation for milk production. The breasts become larger, heavier, and may feel lumpy as the milk-producing structures develop. During breastfeeding, blocked milk ducts can cause temporary lumps that may be tender.

At menopause, the glandular tissue in the breasts gradually replaces with fatty tissue. This can make breasts feel softer than before. Some people notice their breasts become smaller, while others find them more tender during the hormonal transition of perimenopause.

When Should You See a Doctor for a Breast Lump?

You should see a doctor if you discover any new lump in your breast. Also seek prompt medical attention for lumps that do not go away after your menstrual period, changes in breast shape or size, skin changes like dimpling or puckering, nipple discharge (especially if bloody), nipple inversion, or swollen lymph nodes in your armpit.

Finding a new lump in your breast can be worrying, but it is important not to delay getting it checked. While most breast lumps turn out to be benign, only proper medical evaluation can determine this. The key message is simple: any new breast lump should be examined by a healthcare provider.

If you notice a lump just before your period, it may be reasonable to wait until after your period ends and check again. Lumps related to hormonal changes often resolve once menstruation begins. However, if the lump persists after your period or if you are postmenopausal, you should schedule an appointment to have it evaluated.

Beyond lumps, there are other breast changes that warrant medical attention. Contact your healthcare provider if you notice any of the following:

• Changes in breast size or shape that are not related to your menstrual cycle, weight changes, or age
• Skin changes on the breast including dimpling, puckering, redness, thickening, or an orange-peel texture (peau d'orange)
• Nipple changes such as inversion (turning inward), scaling, crusting, or unusual rash
• Nipple discharge, especially if it is bloody, occurs spontaneously (without squeezing), or comes from only one breast
• Persistent breast pain that is not related to your menstrual cycle and does not improve
• Swollen lymph nodes in your armpit or around your collarbone

How Can You Examine Your Own Breasts?

Breast self-awareness means knowing how your breasts normally look and feel so you can notice changes. While formal monthly self-examinations are no longer universally recommended, being familiar with your breasts helps you detect changes that should be evaluated. The key is knowing your own normal.

Medical guidelines have evolved regarding breast self-examination (BSE). While formal monthly self-exams were once widely recommended, research has not shown that they reduce breast cancer mortality when used alone. However, many breast cancers are first detected by patients who notice a change in their breasts. For this reason, current guidance emphasizes breast self-awareness rather than formal monthly examinations.

Breast self-awareness means being familiar with how your breasts normally look and feel throughout your menstrual cycle. This includes knowing their usual size, shape, texture, and any areas that are normally lumpy or tender. When you know your baseline, you are better able to notice changes that may warrant medical evaluation.

If you choose to perform regular breast self-examinations, the best time is a few days after your period ends when your breasts are least likely to be tender or swollen. For postmenopausal women or those who do not menstruate, choosing a consistent day each month (such as the first of the month) can help establish a routine.

Steps for breast self-examination

If you want to perform a thorough breast examination, follow these steps:

Visual inspection: Stand in front of a mirror with your arms at your sides. Look at your breasts for any changes in size, shape, contour, or skin texture. Look for dimpling, puckering, redness, or nipple changes. Repeat this inspection with your arms raised overhead and while pressing your hands firmly on your hips (which tenses the chest muscles).

Physical examination while standing: Using the pads (not tips) of your three middle fingers, examine your entire breast using small circular motions about the size of a coin. Use three different pressure levels: light pressure for the tissue just beneath the skin, medium pressure for the middle tissue, and firm pressure for the deep tissue near the chest wall. Cover the entire breast from your collarbone to below your breast, and from your armpit to your cleavage. You can perform this exam in the shower when your skin is slippery.

Physical examination while lying down: Lie down and place a pillow under your right shoulder. Put your right arm behind your head. Using your left hand, examine your right breast using the same circular motion technique. The breast tissue spreads out more evenly when you are lying down, making it easier to feel the entire breast. Repeat for the other side.

Check your nipples: Gently squeeze each nipple to check for any discharge. Note any changes in nipple appearance.

Check your armpits: Feel the area under each arm for any lumps or swelling while your arm is only slightly raised.

How Are Breast Lumps Diagnosed?

Breast lump diagnosis typically involves a clinical breast examination by a doctor, followed by imaging tests such as mammography and/or ultrasound. If the imaging is inconclusive or concerning, a biopsy (fine needle aspiration or core needle biopsy) may be performed to examine cells under a microscope. Results are usually available within 7-10 days.

When you visit a healthcare provider for a breast lump, the evaluation typically follows a systematic approach known as "triple assessment." This involves clinical examination, imaging studies, and, if needed, tissue sampling (biopsy). This comprehensive approach helps ensure accurate diagnosis.

Clinical breast examination

Your doctor will begin by asking you questions about the lump and your medical history. They will want to know when you first noticed the lump, whether it has changed in size, whether it is painful, and whether it changes with your menstrual cycle. They will also ask about your personal and family history of breast or ovarian cancer, your menstrual history, pregnancies, breastfeeding, and any medications or supplements you take.

The doctor will then perform a physical examination of both breasts. They will feel (palpate) the breast tissue systematically to characterize any lumps - noting their size, shape, texture, mobility, and location. They will also examine the lymph nodes in your armpits and around your collarbone, as cancer can spread to these areas.

Mammography and ultrasound

After the clinical examination, imaging tests help visualize the lump and surrounding tissue. Mammography is an X-ray of the breast that can detect many abnormalities, including some that cannot be felt. Mammography is particularly useful for detecting calcifications (tiny calcium deposits) that may indicate cancer.

Ultrasound uses sound waves to create images of breast tissue and is particularly helpful for distinguishing between solid masses and fluid-filled cysts. Ultrasound is often used in addition to mammography, especially in women with dense breast tissue or to further evaluate a lump seen on mammogram. It is also the first-line imaging test for women under 30, as mammography is less effective in younger women with denser breast tissue.

Biopsy

If imaging shows a suspicious area, or if the doctor wants to confirm the nature of a lump, a biopsy may be performed. A biopsy involves removing a small sample of tissue or cells for examination under a microscope by a pathologist.

There are several types of breast biopsy:

• Fine needle aspiration (FNA): A thin needle is inserted into the lump to withdraw cells or fluid. This is often used to drain cysts or to sample cells from a solid lump.
• Core needle biopsy: A larger needle is used to remove small cylinders of tissue. This provides more tissue for analysis and can determine if a cancer is invasive.
• Surgical biopsy: Sometimes the entire lump or a large portion is removed surgically for examination. This may be done if needle biopsies are inconclusive or if the lump needs to be removed regardless of the diagnosis.

Most biopsies can be done under local anesthesia in an outpatient setting. Results are typically available within 7-10 days, though this can vary depending on the facility and the complexity of the analysis needed.

What Is a Fibroadenoma?

A fibroadenoma is the most common benign (non-cancerous) breast tumor, especially in women under 30. Fibroadenomas are solid, smooth, rubbery lumps that move easily under the skin. They are caused by overgrowth of fibrous and glandular tissue. Most fibroadenomas do not require treatment and can be monitored safely.

Fibroadenomas develop when a part of the breast glandular tissue grows faster than the surrounding tissue, creating a smooth, firm lump. They are composed of both fibrous (connective) tissue and glandular (epithelial) tissue, hence the name "fibro-adeno-ma."

These benign tumors are most common in women between the ages of 15 and 35, though they can occur at any age. They are more common in Black women and in women who use oral contraceptives before age 20. Fibroadenomas often shrink after menopause unless hormone replacement therapy is used.

Fibroadenomas are typically described as feeling like a marble in the breast - smooth, round or oval, rubbery, and easily movable. They are usually painless, though some women experience mild tenderness. They can range in size from smaller than a pea to larger than a golf ball, though most are between 1-3 centimeters.

Fibroadenomas are benign and do not increase breast cancer risk (with rare exceptions like "complex fibroadenomas"). For this reason, many fibroadenomas do not require treatment and can simply be monitored. However, your doctor may recommend removal if the fibroadenoma is large, growing, causing anxiety, or if there is any diagnostic uncertainty.

What Are Breast Cysts?

Breast cysts are fluid-filled sacs within the breast tissue. They are very common, especially in women aged 35-50, and are most prevalent during the years around menopause when breast tissue is transforming. Cysts can appear and disappear quickly, may be tender (especially before periods), and are almost always benign.

Breast cysts develop when fluid accumulates in the breast glands. They can form at any age but are most common during the transition years around menopause, when the breast tissue is undergoing significant changes. After menopause, cysts typically become less common unless hormone replacement therapy is used.

Cysts can range in size from very small (microcysts visible only on imaging) to large enough to be felt easily (macrocysts). They may feel smooth, round, and movable, similar to a grape beneath the skin. Cysts can be single or multiple and may affect one or both breasts. They can appear suddenly and may resolve just as quickly on their own.

A rapidly growing cyst can be painful, especially in the days before menstruation when hormones cause breast tissue changes. Many women notice their cysts become more noticeable and tender before their period, then improve afterward.

Most cysts do not require treatment. They can be definitively diagnosed with ultrasound, which shows their fluid-filled nature. If a cyst is large or painful, your doctor can drain it using fine needle aspiration - inserting a thin needle to withdraw the fluid. This typically relieves pain immediately and causes the lump to disappear. The fluid is sometimes sent for analysis, though simple cysts rarely contain abnormal cells.

If a cyst returns in the same location after being drained, your doctor may recommend further evaluation or closer monitoring.

What Are Fibrocystic Breast Changes?

Fibrocystic breast changes refer to generalized lumpiness and tenderness in the breasts, often varying with the menstrual cycle. This is not a disease but a normal variation that affects up to 50-60% of women. Symptoms typically include diffuse lumpiness, breast pain, and tenderness that worsens before periods.

Fibrocystic changes are so common that many doctors no longer consider them a "condition" but rather a normal variation in breast tissue. The term describes breasts that feel generally lumpy or nodular, often with associated tenderness that fluctuates with the menstrual cycle.

Women with fibrocystic changes often describe their breasts as feeling "ropy" or having areas of thickening scattered throughout. Unlike a distinct lump, these changes tend to be diffuse, affecting larger areas of the breast, and often both breasts. The changes can make breast self-examination challenging because the breast tissue has a naturally lumpy baseline.

The exact cause of fibrocystic changes is not fully understood, but they appear to be related to how breast tissue responds to normal hormonal fluctuations. Symptoms typically begin in the 20s or 30s, peak in the late 30s and 40s, and usually improve after menopause when hormone levels decline.

There is no specific treatment for fibrocystic changes since they are not a disease. However, if symptoms are bothersome, various strategies may help:

• Wearing a well-fitting, supportive bra
• Limiting caffeine intake (though evidence is mixed)
• Taking over-the-counter pain relievers for breast discomfort
• Applying warm or cold compresses
• Reducing dietary fat and increasing fiber (may help some women)

Fibrocystic changes do not increase the risk of breast cancer. However, the lumpy texture can make it more challenging to detect new lumps, which is why regular mammographic screening is important.

What Is Fat Necrosis in the Breast?

Fat necrosis occurs when fatty tissue in the breast is damaged and does not heal properly. The damaged fat cells can form firm, round lumps or areas of calcification. Common causes include trauma to the breast, surgery, or radiation therapy. Fat necrosis is benign and does not increase cancer risk.

When fatty tissue in the breast is injured, it can die and form scar tissue. This process is called fat necrosis. The damaged fat cells may form a firm, round lump that can sometimes be felt. These areas may also develop calcifications (calcium deposits) that can appear on mammograms.

Fat necrosis can occur after any injury to the breast, including car accidents (seatbelt injuries), sports injuries, falls, or even minor bumps that you might not remember. It is also common after breast surgery (including biopsies, lumpectomy, or breast reconstruction) and after radiation therapy for breast cancer.

Fat necrosis is more common in people with larger, fattier breasts and in those with obesity. It can also occur in people with certain conditions that affect small blood vessels, such as diabetes.

When fat necrosis produces a palpable lump, it can feel firm or hard and may be mistaken for cancer. It may or may not be painful. On mammogram, fat necrosis can sometimes produce calcifications that look similar to those associated with cancer, which is why biopsy may be necessary to confirm the diagnosis.

Fat necrosis is benign and does not require treatment unless it is causing symptoms or if there is diagnostic uncertainty. If a biopsy confirms fat necrosis, no further treatment is usually needed. The lump may gradually become smaller over time, though some areas of fat necrosis remain stable.

What Is Breast Inflammation (Mastitis)?

Mastitis is inflammation of the breast, most commonly occurring during breastfeeding when milk ducts become blocked and bacteria enter through cracked nipples. Symptoms include breast pain, warmth, redness, swelling, and often fever. Non-breastfeeding mastitis can also occur, particularly in smokers, and may be mistaken for a breast lump.

Mastitis causes the breast tissue to become inflamed, resulting in pain, swelling, warmth, and redness. It may feel like one or more tender lumps or a diffuse area of firmness. Mastitis is often accompanied by flu-like symptoms such as fever, chills, and body aches.

Mastitis while breastfeeding

Lactational mastitis is the most common form, affecting approximately 10-20% of breastfeeding mothers, typically in the first few weeks of nursing. It usually develops when milk becomes backed up in the breast (milk stasis) and bacteria enter through cracks or breaks in the nipple skin.

When a milk duct becomes blocked, the backed-up milk can irritate the surrounding tissue, causing inflammation. If bacteria (usually Staphylococcus aureus from the baby's mouth or the mother's skin) enter through damaged nipples, the inflammation can become infected.

The best treatment for breastfeeding mastitis is continued breastfeeding or pumping to keep milk flowing and relieve the blocked duct. Applying warm compresses and massaging the breast toward the nipple can help. If symptoms do not improve within 12-24 hours, or if you have fever, antibiotics may be needed.

If mastitis is not adequately treated, it can progress to a breast abscess - a collection of pus that forms a painful lump. Abscesses require drainage (either with a needle under ultrasound guidance or through a small incision) and antibiotics.

Mastitis without breastfeeding

Non-lactational mastitis is less common but does occur, particularly in smokers. Smoking is thought to damage the milk ducts behind the nipple, causing them to become dilated and filled with secretions. This creates an environment where bacteria can grow, leading to recurrent infections.

Non-breastfeeding mastitis typically presents as a painful area near the nipple, often at the edge of the areola (the darker skin around the nipple). It may form an abscess that needs to be drained. Because it can recur, your doctor may recommend mammography after the infection has resolved to ensure there is no underlying breast cancer (though this is uncommon).

What About Breast Cancer?

Breast cancer is the most common cancer in women worldwide. While most breast lumps are not cancer, the risk increases with age - particularly after 50. Warning signs include a hard, painless lump that does not move easily, skin changes, nipple inversion or discharge, and swollen lymph nodes. Early detection through screening and prompt evaluation of changes significantly improves outcomes.

Breast cancer occurs when cells in the breast begin to grow uncontrollably. These cells can form a tumor that can often be felt as a lump or seen on imaging. While breast cancer is a serious disease, significant advances in detection and treatment mean that many breast cancers can be treated successfully, especially when found early.

The risk of breast cancer increases with age. While breast cancer can occur at any age, the majority of cases are diagnosed in women over 50. Family history also plays a role - having a first-degree relative (mother, sister, daughter) with breast cancer approximately doubles your risk. Inherited genetic mutations, particularly in the BRCA1 and BRCA2 genes, significantly increase risk.

Other risk factors include early onset of menstruation, late menopause, never having children or having first child after age 30, long-term use of hormone replacement therapy, obesity (particularly after menopause), alcohol consumption, and a personal history of breast cancer or certain benign breast conditions.

Warning signs of breast cancer

While breast cancer often does not cause symptoms in early stages (which is why screening mammography is so important), there are warning signs to be aware of:

• A new lump or mass: Cancerous lumps are often (but not always) hard, painless, and have irregular edges. However, some cancers are soft, round, or tender.
• Skin changes: Dimpling, puckering, thickening, or redness of the breast skin. An "orange peel" texture (peau d'orange) can indicate inflammatory breast cancer.
• Nipple changes: Nipple turning inward (inversion), scaling, flaking, or crusting of the nipple or areola.
• Nipple discharge: Spontaneous discharge (without squeezing), especially if bloody or from only one breast.
• Swelling: Swelling of all or part of the breast, even without a distinct lump.
• Swollen lymph nodes: Lumps or swelling in the armpit or around the collarbone.

Breast cancer screening

Screening mammography can detect breast cancer before it causes symptoms, when it is most treatable. Guidelines vary by country and organization, but most recommend regular mammography screening beginning between ages 40-50 for women at average risk, continuing until at least age 74.

If you have a higher risk of breast cancer due to family history, genetic mutations, or other factors, your doctor may recommend beginning screening earlier, having more frequent mammograms, or additional screening with breast MRI.

Can Men Get Breast Lumps?

Yes, men can develop breast lumps. The most common cause in teenage boys is gynecomastia (swelling behind the nipple during puberty). In adult men, breast lumps can also be caused by gynecomastia, cysts, or medications. While rare, men can develop breast cancer - approximately 1% of breast cancers occur in men. Any new breast lump in a man should be evaluated by a doctor.

Although breasts are generally considered a female characteristic, men also have breast tissue (though less developed) and can therefore develop breast conditions, including lumps.

Gynecomastia

The most common cause of breast lumps in males is gynecomastia - enlargement of the glandular tissue in the breast. In teenage boys, it is extremely common during puberty when hormone levels are fluctuating. It typically appears as a rubbery or firm mound of tissue behind the nipple that may be tender. It often affects both sides, though it can be more prominent on one side.

Pubertal gynecomastia usually resolves on its own within 6 months to 2 years as hormone levels stabilize. No treatment is usually needed, though it can cause embarrassment and psychological distress for some teenagers.

In adult men, gynecomastia can be caused by various factors including obesity (increased body fat leads to higher estrogen levels), certain medications (including some blood pressure drugs, anti-ulcer medications, and drugs for prostate conditions), liver or kidney disease, excessive alcohol use, and conditions affecting hormone production.

Male breast cancer

While rare, men can develop breast cancer. Approximately 1% of all breast cancers occur in men. Because it is uncommon, men are often diagnosed at a later stage when the cancer has already spread. Risk factors for male breast cancer include older age, family history of breast cancer, BRCA2 gene mutations, Klinefelter syndrome, liver disease, obesity, and radiation exposure.

Symptoms of male breast cancer are similar to those in women: a painless lump in the breast (usually just below or around the nipple), nipple discharge, nipple inversion, or skin changes. Because men have less breast tissue, cancers may spread to the skin or chest wall earlier.

Any man who notices a new breast lump should have it evaluated by a doctor. While most male breast lumps are not cancer, early detection is important for those that are.