Dr Phil Kieran: Should we worry about my teenage son's short stature?

When and how much we grow is a highly variable part of adolescence but, on average, boys’ pubertal growth spurt occurs around age 12. Picture: iStock 

My 16-year-old son is easily the shortest in his class. It’s beginning to undermine his confidence, particularly as he is being teased about his height. My husband is over 6ft tall, and his older brother shot up around 14. Is it just a matter of time before he has a growth spurt or should we seek medical advice?

Height is a complex and sensitive topic that can be normal or indicate a medical issue that may need treatment.

When and how much we grow is a highly variable part of adolescence but, on average, boys’ pubertal growth spurt occurs around age 12 (with a range of nine to 14). This can be influenced by a number of factors, such as genetics (were the parents early or late in starting puberty?), environment (very low body weight can delay puberty a little), and individual response to the hormones released during puberty.

From a genetics standpoint, you can roughly estimate your child’s predicted adult height by looking at the parents’ height. First, find the average of their heights by adding them together and dividing by two. When predicting the height of a boy, add 13cm (about 5in), and for a girl, subtract 13cm. This result, plus or minus 8cm (3in), will give a guide to the child’s expected height when fully grown.

You mention your husband is above average height and your older son grew more quickly. This means there may be an issue with your younger boy’s growth. This could be caused by a delay of puberty (which can be normal or not) or a problem with growth hormone.

Your GP will be able to make a physical examination and assess approximately how far along in puberty your son is, and compare this with how tall we would expect him to be. If this is outside the expected ranges, I would recommend seeing a paediatric endocrinologist. The likely next step could be an X-ray of the bones, which can provide a different view of how far along puberty is.

The endocrinologist may also consider doing more specialised blood tests at this point. After these investigations, you may find his growth is just a bit delayed and will start normally, or you may find there is an issue, which the endocrinologist can advise on treatment. Mostly, if an issue is found, a treatment option is available.

“Normal” male height ranges from 159cm to 193cm (5ft 2in to 6ft 4in) and can be a cause of much distress. This can be from male peers calling each other short or gangly, or girls talking about how they’d never look at a boy below a certain height.

We should all be conscious of how we talk to our children about height and physical differences, and encourage them not to judge others on something outside their control.

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