Reasons for Sudden Breast Growth

Both women and men can experience sudden breast growth, though it is much for common for women. Breast growth is often due to normal, hormonal changes. But sometimes, it is a symptom of an underlying medical condition. Here are possible reasons for breast to suddenly increase in size:

Breast Growth in Men

As you likely know, girls' breasts grow during puberty. But it's perfectly normal for boys to also experience breast growth (gynecomastia) as they mature, according to the Mayo Clinic.

Both males and females have certain amounts of the hormones estrogen and testosterone. Estrogen is responsible breast growth in females while testosterone controls male physical characteristics like body hair and muscle mass, according to the Cleveland Clinic. So it makes sense that females have more estrogen while males have more testosterone.

However, the balance of these hormones can change during puberty, per the Mayo Clinic. If boys (typically during ages 12-14) have a greater estrogen- to-testosterone ratio, it can cause breasts to grow. Typically, the swollen breast tissue will go away on its own after 6 months to two years.

Gynecomastia can also affect males at other points in their lives, including right after birth and between ages 50-80, per the Cleveland Clinic. Additionally, certain medical conditions such as liver disease, hypogonadism, hyperthyroidism, or tumors in the tesitcals or adrenal glands can cause gynecomastia. Antibiotics, some mental health medications, marijuana, anabolic steroids (sometimes used by bodybuilders), and illicit drugs such as heroin can also cause sudden breast growth in men.

Read more: How to Get Rid of Man Boobs Without Going to the Gym

Changes in Weight

Weight gain can cause breasts to grow in both women and men. Gaining weight causes excess fat deposits, meaning fat can accumulate in the breasts, causing them to grow, according to Harvard Medical School.

It makes sense that weight gain can cause breast growth. But it may surprise you to learn that a severe lack of nutrition can cause breast growth in men. When the male body is malnourished, testosterone levels drop but estrogen levels stay the same, per the Mayo Clinic. As discussed, higher estrogen levels can cause gynecomastia.

Pregnancy and Breast Growth

Female breasts tend to grow larger during the menstrual cycle, according to Johns Hopkins Medicine. In the second half of the cycle-- after ovulation-- a key female hormone called progesterone stimulates the formation of milk glands in the breast. This can cause breast swelling, soreness, and tenderness. If a woman doesn't become pregnant, breasts will return to their normal size.

If conception does occur, the body will continue to release progesterone, per Johns Hopkins Medicine. Breast growth, along with breast soreness or a tingling sensation in the nipples is one of the earliest signs of pregnancy. Breasts will continue to grow until about the 5th or 6th month of pregnancy by which point the breast are fully capable of producing milk for the baby once it's born.

Read more: Hormone Treatments for Breast Growth

A Possible Breast Infection

If the skin of the breast or nipple becomes irritated or cracked, bacteria can enter the breast, causing an infection, or mastitis, according to Mayo Clinic. Mastitis typically affects women who are breastfeeding but it can affect both women and men at any time.

The symptoms of mastitis can appear very quickly, per the Mayo Clinic. One of the most common symptoms is swelling in the affected breast. Other symptoms include breast tenderness, skin that is warm to the touch, pain or a burning sensation, skin redness, and flu-like symptoms including a fever. Mastitis is usually cleared up with antibiotics.

Inflammatory Breast Cancer

Sudden breast growth is not generally not a sign of breast cancer. Sometimes, however, it can be a symptom of a type of cancer called inflammatory breast cancer (IBC). This type of cancer is aggressive but also very rare; it accounts for only 1-5% of all breast cancers, according to the American Cancer Society. Though women are more likely to get breast cancer (because they have more breast tissue) men can also develop breast cancer, including IBC.

The most common symptoms of IBC include breast swelling in the affected breast, red or purple colored skin, and dimpling or thickening of the breast skin, like the peel of an orange, per the American Cancer Society.

Roshni Rao, MD, Chief of the Breast Surgery Program at Columbia University Medical Center tells that, "Inflammatory breast cancer is easy to miss. It doesn't have an actual mass [tumor] associated with it," says Rao. Not only does IBC not present with breast lumps, the most common symptoms-- namely breast swelling and redness-- look like a breast infection. "If [a patient] is put on antibiotics [for a breast infection] but the symptoms don't go away, that's a concern," says Rao. She adds that patients should not ignore their symptoms but should be properly evaluated by a doctor. "A skin biopsy is the only real way to rule out inflammatory breast cancer," says Rao.