Breasts development in teenage boys and men
How breasts develop?
Even a newborn baby has some basic breast tissue, which started to develop when it was a 6-week-old fetus. Before puberty, the breasts are the same in girls and boys. They consist of tiny branching tubes embedded in packing tissue. The glands for making milk have not yet formed.
At puberty, hormone levels start to rise. In females, the main hormone is oestrogen (the 'female hormone'). Oestrogen makes the tubes thicken, lengthen and become more branched, and also stimulates the development of glandular lobules. In men, the main sexual hormone is testosterone. This is made mainly in the testicles. The level of testosterone rises at puberty to 30 times the level it was previously. Men normally also have a small amount of oestrogen; at puberty, it rises to only three times the level it was before. This often makes the breast tissue grow slightly in teenage boys (see below), but eventually the high levels of testosterone take over completely and prevent the oestrogen having any further effect on the breast. Therefore glandular lobules do not form in men. Instead, the breasts flatten out, and remain as a collection of tubes in packing tissue, just as they were before puberty.
Breast growth in teenage boys Teenage boys sometimes notice that their breasts are enlarging and/or are tender. This is nothing to worry about, and happens to about half of all boys at some time. It does not mean you are changing sex! It can start anytime after the age of about 10, and the breasts may be quite large by the age of 13 or 14. In the mid-to-late teens, they start to become smaller again, and will usually have flattened out by age 18 or 19.Why it happens. At puberty, the testosterone level does not rise steadily. Over the first few teenage years, it fluctuates wildly constantly, and on some days the level will dip quite low. These dips in testosterone allow the small amount of oestrogen, which circulates in the blood of all men, to have an effect on the breast. This stimulates the growth of the packing tissue and tubes, so that the breasts enlarge. In men over about 15 years of age, the testosterone settles at a more steady, high level. This prevents the oestrogen from having an effect any longer, and the breast tissue usually starts to shrink.
In only a few boys, the breasts may remain enlarged at the end of the teen years. This is not usually because there is anything wrong with the male hormones, but because the enlarged breast tissue has remained hypersensitive to the tiny normal amounts of oestrogen, or else is not responsive to the 'shutting down' effect of testosterone. Your doctor can check your hormone levels, and if everything is normal (which it usually is) a surgeon can remove the excess breast tissue.
The breasts can enlarge if you are overweight, simply because fat has settled there. They can also enlarge because the actual breast tissue is overdeveloped. To decide which it is, lie flat and grasp your 'breast' tightly between your thumb and forefinger. Then gradually move your finger and thumb towards the nipple. If you can feel a firm, rubbery disk-like mound of tissue which is more than 2 cm across, and which seems to be stuck to the back of the nipple and to the pink area surrounding the nipple (areola), it is likely that the breast tissue is overdeveloped. The area may feel tender. Usually both breasts are equally affected, but sometimes development of one is more obvious than the other. If one breast is more enlarged than the other, it would be sensible to ask your doctor to check it; breast cancer is rare in men, but it can occur. If there is no distinct mound of tissue under the nipple, it may simply be that you are too fat.
Alcohol abuse upsets both sides of the oestrogen:testosterone balance. It stimulates the liver to clear testosterone from the blood, so testosterone levels fall. It probably also reduces the ability of the liver to break down oestrogens, so levels rise. Fortunately, the liver can often recover if alcohol intake is reduced.
Tumours are a rare cause of breast enlargement. Breast cancer can occur in the male breast, but is usually on one side only. Tumours in other parts of the body can sometimes produce hormones that make the breasts grow and may also cause impotence and/or oozing of milk from the breast. If you have these symptoms, it is essential that you see your doctor straight away.
Breast cancer in men Breast cancer can occur in men. It kills about half the men who get it, whereas only about one-quarter of females with breast cancer die from the disease. This difference is because men with breast cancer do not go to their doctor early enough. Therefore men are dying from breast cancer because they didn’t know about the disease or they were too embarrassed to seek help.
And by the time they get treatment, the cancer has spread. This is a shame, because breast cancer is just as treatable in men as in females if it is found early enough. So if you have the slightest worry that you might have a lump in your breast, see your doctor straight away so that you can have tests and treatment if necessary. Other signs of breast cancer include a sore or rash on the nipple, discharge from the nipple, the nipple turning in, or a change in shape of the breast. If you are a female reading this, try to educate the men in your life about male breast cancer.
Old age is natural for men's breasts to enlarge. This often seems to happen over a few months, after which no further enlargement occurs. The reason is partly that less testosterone is produced in old age. Also, in old age, the body often contains a higher proportion of fat, which produces oestrogens. In about 50% of people, the breasts will become smaller again in time.