What is a tongue-tie?

A tongue-tie (also known as Ankyloglossia) is caused by a short or tight membrane under the tongue (the lingual frenulum).

Where the membrane is attached at, or close to the tongue tip, the tongue tip may look blunt, forked or have a heart shaped appearance. However, where the membrane is attached further back the tongue may look normal.

Research suggests that approximately 1 in 10 babies may be born with some membrane under the tongue. But only about half of those babies display significantly reduced tongue function, making breast or bottle feeding difficult.

These babies are likely to benefit from treatment to release the restriction that the membrane is having on the tongue and enable to baby to feed effectively.

Tongue-tie assessment.

Tongue-tie practitioners often talk to parents who have had conflicting advice around whether or not their baby has a tongue-tie so it may be helpful for parents, and professionals who do not assess and divide tongue-ties, to have an understanding of what an assessment for tongue tie involves.

The decision on whether or not a tongue-tie is impacting on feeding and whether it is appropriate to offer to divide it should be made after a detailed feeding history has been taken. This will usually include information about the pregnancy and birth and the medical history of both mum and baby. The baby is usually observed at the breast. This may be done by the person who divides tongue-ties or by someone who has been supporting you with feeding, prior to you being referred for division, such as a MW, HV or breastfeeding counsellor/lactation consultant. The function of the tongue will also be assessed to establish if the baby is tongue-tied and if this is impacting on feeding.

Assessment for tongue-tie requires training and skill and involves placing a finger in the baby's mouth. It cannot be done by just taking a look. Assessment is usually carried out with the baby on the assessor's lap or a flat surface such as a table or couch. It involves observing how the baby uses their tongue. Professionals assessing babies for tongue-ties should assess elevation, lateralisation and extension. Elevation can most easily be assessed when baby cries. With the mouth wide open, the tongue tip should lift up to at least the mid mouth. In tongue-tied babies the tongue often stays quite flat in the floor of the mouth or the edges curl up to form a bowl shape or 'v' shape. Babies should be able to poke their tongue tip out well over the bottom lip when the bottom lip is stimulated. When the assessor runs their finger along the top ridge of the bottom gum the tip of the baby's tongue should follow the finger so the tongue sweeps side to side (lateralisation). Some assessors perform a suck assessment by placing their finger in the baby's mouth (pad side up, nail side down) and feeling how the baby is cupping and using their tongue. Assessors sweep their finger under the baby's tongue so they can feel the extent of the tongue tie and the tongue will also be lifted to visualise the frenulum.

The appearance of the frenulum is also documented including the shape of the tongue tip, where it attaches to the floor of the mouth and the underside of the tongue and how long and stretchy it is.

The video clip below shows part of an assessment for tongue-tie.

Problems which may be due to a tongue-tie:


  • Sore/damaged nipples
  • Nipples which look misshapen or blanched after feeds
  • Mastitis
  • Low milk supply
  • Exhaustion from frequent/constant feeding
  • Distress from failing to establish breastfeeding


  • Baby
  • Restricted tongue movement
  • Small gape resulting in biting/grinding behaviour
  • Unsettled behaviour during feeds
  • Difficulty staying attached to the breast or bottle
  • Frequent or very long feeds
  • Excessive early weight loss/ poor weight gain/faltering growth
  • Clicking noises and/ or dribbling during feeds
  • Colic, wind, hiccoughs
  • Reflux (vomiting after feeds)

Your baby may not display all of these signs and there can be other causes for these symptoms so thorough assessment by a practitioner skilled in breastfeeding is essential.

For more detail please see our new ATP 'Breastfeeding and Tongue Tie' leaflet click here