A speech and language therapist explains the causes of stammering and Jamal, a university student, talks about learning to live with his stammer.

Media last reviewed: 14/05/2013

Next review due: 14/05/2015

Child health 6-15

Information on child health, including healthy diet, fitness, sex education and exam stress

Stammering  or stuttering  is a relatively common speech problem that can occur in childhood and persist into adulthood.

Stammering is characterised by the repetition of sounds or syllables (such as saying ‘mu-mu-mu-mummy’), prolonging sounds (mmmmmmummy) and pausing or 'blocking' (when a word gets stuck or doesn't come out at all).

It usually occurs at the beginning of speech, and people will often avoid certain words or speaking situations to try to hide it.

Stammering varies in severity from person to person. A person might find that they have periods of stammering followed by times when they speak relatively fluently.

Read more about the signs of stammering.

Types of stammering

There are two main types of stammer:

  • Developmental stammering is the most common type of stammering that many people are familiar with. It develops during childhood as a child is first learning how to speak, and usually begins around the age of three-and-a-half years.
  • Acquired or late-onset stammering can occur in older children and adults as the result of a severe head injurystroke or progressive neurological disease (disease affecting the nervous system). It can also be caused by certain drugs or medication, or psychological or emotional trauma.

The rest of this article will focus on developmental stammering.

Who is affected by stammering?

Stammering is common in young children. Estimates for developmental stammering vary, but it is expected that 5-8% of pre-school age children will experience a phase of non-fluent speech.

The condition is more likely to persist in males than females, which is why there are four times more men than women with a stammer. The reason for this is unclear.

All ethnic groups are affected equally by stammering.

The causes of stammering are still uncertain, but evidence suggests that inheriting certain genes may increase a child's likelihood of developing a stammer. Read more about the causes of stammering.

Treating stammering

About three in four cases of developmental stammering in pre-school children will resolve without treatment.

One in four children will need therapy to stop a persistent stammer developing. Treatment is highly successful in resolving stammers in pre-school age children, especially if it is received as soon as possible. Stammers are less likely to be totally eliminated in children over the age of six.

A speech and language therapist is trained to identify children whose stammers are likely to resolve naturally and which children need therapy, so early referral is key. Read more about diagnosing stammering.

Without adequate treatment, about 1% of older children and teenagers will have developed a persistent stammer. It is estimated that 1 in every 100 adults has a stammer.

Some adults find their stammering improves as they get older. Many will have learnt to control their stammer most of the time, although certain ‘triggers’ may make them stammer more, such as stress or having to speak in public.

There are many different speech and language therapy approaches to stammering that can help people to improve their fluency and communication skills. 

Electronic ‘anti-stammering’ devices are also available and can be helpful for some people. These are designed to help people control their speech by giving them sound feedback. 

Read more about how stammering is treated.

Page last reviewed: 27/07/2012

Next review due: 27/07/2014


How helpful is this page?

Average rating

Based on 26 ratings

All ratings

Add your rating


The 1 comments posted are personal views. Any information they give has not been checked and may not be accurate.

PaulCooper said on 16 November 2012

Are any of these therapies available through the NHS, i.e. is it worth mentioning it to my GP?

Report this content as offensive or unsuitable