Late Bloomer: Signs of Late Puberty and How Much You Will Grow

A late bloomer is a healthy teen who starts puberty and the growth spurt later than most friends, then keeps growing for longer. Doctors call this constitutional delay of growth and puberty. It is the most common cause of both short height and late puberty in teens, affects over 2% of adolescents (mostly boys), and usually runs in families. Most late bloomers catch up and end up within the normal adult height range.

What does "late bloomer" mean?

Puberty normally starts between 8 and 13 in girls and between 9 and 14 in boys. A late bloomer is at the far end of that range or just past it. Doctors usually start asking questions when a boy has no testicle growth by 14 or a girl has no breast development by 13.

"Constitutional" means the delay comes from the body's own built-in timing rather than an illness. It is considered a variation of normal, not a disease. The catch is that a few medical conditions can look the same at first, so a doctor has to rule them out before calling someone a late bloomer.

Late bloomer signs in boys

• You have been one of the shortest in your class for years, while still growing steadily each year.
• Puberty has barely started by 13 or 14: little or no testicle growth, little pubic hair, and a voice that has not changed.
• Your friends have shot up and you have not. Your growth spurt simply has not arrived yet.
• Your growth may slow a little just before puberty, which can make the height gap with friends look even bigger for a while.
• A parent or relative was a late developer. Between half and three-quarters of teens with constitutional delay have a family history of late puberty.
• You look younger than your age and may be slim, sometimes with a little fat around the hips or chest.

Late bloomer signs in girls

For girls, the main signs are no breast development by about 13, a first period that has not come by about 16, and a growth spurt that has not yet happened while friends have had theirs. A family history of late periods makes constitutional delay more likely. Very low body fat, for example in dancers, runners and swimmers, or not eating enough can also delay puberty.

Am I a late bloomer?

Ask yourself four questions:

1. Am I 13 or older (girls) or 14 or older (boys) with few or no signs of puberty?
2. Am I short for my age but still growing at a steady rate each year?
3. Did one of my parents develop late, for example a dad who kept growing after high school or a mom whose first period came at 14 or later?
4. Am I otherwise healthy, with normal energy, appetite and digestion?

If you answered yes to most of these, you may well be a late bloomer, but only a doctor can confirm it. The Am I done growing? quiz flags late-bloomer patterns based on your age, recent growth and puberty signs.

How doctors diagnose constitutional delay

There is no single test. A doctor will usually:

• Ask about family history, including when each parent went through puberty.
• Review your growth chart and examine you to see how far puberty has progressed.
• Order a bone age X-ray of the left hand and wrist. In late bloomers, the bones usually look younger than their real age, which means the growth plates have more time left to grow.
• Check blood tests for thyroid, growth and sex hormones, and look for conditions such as celiac disease or other chronic illness.

If anything looks unusual, you will usually be referred to a pediatric endocrinologist, a doctor who specializes in growth and hormones.

Do late bloomers end up taller?

This is one of the most common myths. Late bloomers do not usually end up taller than everyone else; they end up roughly where their genes point, just later.

In a long-term study that followed healthy children from infancy to adulthood, early and late developers reached about the same adult height. The main difference was that late developers had slightly longer legs. Late starters also tend to have a somewhat smaller growth spurt, but they have grown for more years before it begins, so it evens out.

Teens with a clinical diagnosis of constitutional delay are a slightly different story. Most reach a height in the normal adult range, but researchers have found that some finish a little below their genetic target, and experts do not fully agree on how often this happens. You can see your own genetic target with the mid-parental height calculator.

How long do late bloomers keep growing?

Late bloomers grow for longer because their growth plates close later. Cleveland Clinic notes that a boy who shows other signs of puberty by 14 will likely still reach his full height, perhaps at 18 instead of 16 or 17. Growth after 18 is uncommon and usually adds an inch or less, and even very late bloomers finish puberty before 25.

For the usual timelines, see when do boys stop growing, and if you are already older, can you grow after 18?

Treatment and support

Most late bloomers need no treatment: puberty starts on its own, and patience plus regular checkups is the usual plan. When the delay is causing real distress, such as bullying, low self-esteem or depression, a pediatric endocrinologist may offer a short course of hormone treatment, often for a few months, to get puberty going. After that, the body usually takes over.

Do not try to speed things up on your own. Hormones used without careful medical dosing can make bones mature faster and close the growth plates early, which can cost you height. Read more in does testosterone make you taller?

Being the smallest in your year can be hard. It helps to find sports and activities where size matters less, talk to someone you trust, and remember that your friends' head start is temporary. While you wait, sleep well, eat enough and stay active, so you are ready to make the most of your growth spurt when it comes.

When to see a doctor

See a doctor if:

• A boy has no testicle growth by 14, or a girl has no breast development by 13.
• A girl's period has not started by about 16, or more than five years after breast development began.
• Puberty started but seems to have stalled.
• Growth slows down sharply or you are dropping to lower percentile lines.
• There are signs of another health problem, such as ongoing stomach trouble, unexplained weight loss or constant tiredness.
• Being late is affecting your mood, school or friendships.

The short version

Being a late bloomer usually just means your body is running on a later clock, often the same one a parent had. You will likely keep growing after your friends stop and end up within the normal adult range, though not necessarily taller than you would have been otherwise. A doctor can confirm it with a few simple checks and help if the wait becomes hard.