Breast development, along with a rapid growth spurt, is the first external sign that a girl is entering puberty. It’s the beginning of a series of changes that will mean her body is gradually transformed from the shape of a child into an adult female figure.
Your daughter is likely to feel excited as her body begins to change. But she may also feel anxious. She may have lots of questions, such as how long will her breasts take to grow? How big will they get? Do they look normal?
What is not widely known is that boys can also experience a small amount of breast development at the start of puberty. If this happens to your son, he’ll need plenty of reassurance that it will settle down.
When do they start growing?
Girls usually start producing sex hormones between the ages of eight and 11, with the average age for beginning puberty at around 11. But this can vary quite a lot. In fact, timing often runs in families. A girl will often start puberty at around the same age her mum or sisters did.
So, while some girls might notice early breast growth around the age of nine, for others it can be as late as 13 or so. Both are perfectly normal.
What’s the process?
Once levels of the sex hormone oestrogen start to rise at the beginning of puberty, a girl’s breasts begin to grow. This happens very gradually. It can take up to four years for the breasts to develop fully.
The first sign of growth is that the nipples begin to stick out slightly from the chest. Behind the nipple, milk ducts begin to grow. The next stage is when the areola, which is the flat, circular part around the nipple, begins to swell. These breast buds can be asymmetrical at first, so your daughter might need reassuring that everything is OK.
The breast then begins to fill out, as fat is deposited around the nipple. At first, the breasts stick out in a cone shape. As they continue to grow, the shape of the breast begins to change with rounder, more adult looking contours.
The final size of a girl’s breasts is hereditary – determined by what size her mum, grandmothers or aunts are – although it is a complex pattern of inheritance. Breast shape can vary a great deal, and is determined by the amount of fatty tissue it contains. They can range from being small (such as bra size AA) to large (such as size FF). All sizes and shapes are normal.
Dealing with discomfort
Many girls find that when their breasts first being to grow, they feel sore and the skin around them feels itchy. This is very normal. The new tissue feels tender, and the skin may feel itchy because it’s stretching. Usually they feel more comfortable after the first year.
Sometimes, because the skin is expanding quickly, the delicate underlying tissue can tear causing thin scars (stretch marks). These will fade in time. There isn’t any evidence that any treatment will help prevent stretch marks, but some women find it helpful to moisturise the area with creams containing vitamin E, cocoa butter or aloe vera.
Every girl’s breasts go through regular changes. As she grows and develops, your daughter may being to notice that her breasts feel swollen and tender just before her period. This is due to the action of female hormones that increase the amount of water retained in the tissues.
She might also notice small breast lumps, which might make her feel worried. We are all very aware of breast cancer and the fact that lumps are associated with this. In fact, in teenagers breast lumps are usually related to normal growth and development. Breast cancer is extremely rare in this age group.
It’s a good idea to encourage your daughter to get into the habit of examining her breasts regularly. This will help her get used to the normal changes that her breasts go through, and will set a helpful pattern for later life. She should check her breasts once a month; the best time is often about a week before her period starts.
Choosing a bra
As your daughter’s breasts grow, she will need a properly fitted bra. For her first bra, make sure she sees a trained fitter. To ensure your daughter feels comfortable, and has proper support, it’s really important that the shoulder straps and underband are a good fit.
What about breast development in boys?
Your son might be alarmed if he beings to experience a small amount of breast development. But it is very common for this to happen, along with breast tenderness, in early puberty.
This is because some of the male hormone, testosterone, is converted to the female sex hormone, oestrogen. In early puberty the levels of testosterone are relatively low and may not be sufficient to prevent the effects of oestrogen on breast tissue.
The result is that often a boy’s nipples and breast can grow slightly. The effect is often more marked if a boy is overweight.
As puberty progresses, testosterone levels rise and this development usually disappears within a year or so. It is worth pointing out that if the problem is very noticeable, or does not settle down, it is best to ask your GP for advice. There are some rare underlying conditions that can be associated with this problem and occasionally treatment may be needed.
Occasionally, a girl might have one (or both) nipples that appear to be inverted at first. It is usually nothing to worry about. As development continues, the nipple will usually revert of its own accord. But it would be worth your daughter seeing her GP.
Very occasionally there can be an underlying problem that can be linked with an inverted nipple, such as a cystic lump underneath it. In this case a referral for more treatment would be needed. But it’s a rare problem and the chances are that development is normal.
If breast budding starts very early, before your daughter reaches the age of seven-and-a-half or eight, it’s best to see your GP. She may need to have investigations to check whether she has a condition known as precocious (early) puberty.