Baby Sucking Thumb

Why Does Your Child Suck Her Thumb and Should You Stop It?

3 min readUpdated April 09, 2025

Related Articles

How to Solve Baby Tooth Problems and Injuries
How to Treat Baby Tooth Problems and Injuries
If you’re worried about your baby’s thumb-sucking, take heart. Until your little one turns about 5 years old, there isn’t any risk associated with thumb-sucking, so it’s only really closer to then that you might consider helping her stop the habit, if they haven't already. Read on to learn more about why do babies suck their thumb, when the behavior typically starts, and how to stop thumb-sucking when the time comes.

Why Do Babies and Children Suck Their Thumbs?

Babies are born with natural rooting and sucking reflexes, which is why some infants will put their thumb or fingers in their mouth and suck.
Thumb-sucking also has a soothing effect for babies and young children. It can help your little one feel secure and comforted, which is why they may pick up the thumb-sucking habit when their needs a little soothing or before bed, for example. So, don’t worry too much about it: It’s perfectly normal for your little one to suck their thumb.

When Do Babies Start Sucking Their Thumb and When Do They Stop?

When do babies start sucking their thumb? Thumb-sucking often starts at a very young age. Some babies begin sucking their thumbs and fingers in the womb! And, some newborn babies start sucking their thumbs as soon as they have been born. There are even babies who won’t go on to suck their thumbs.
Once your little one starts, it can easily become a habit, especially as your little one likely finds it so comforting. It's helpful to remember that thumb and finger sucking is a common habit—and that all kids have habits—so you have no need to worry if your baby is sucking their thumb regularly.
Most children grow out of this behavior. In fact, more than half stop when they are 6 or 7 months old. Others stop naturally a little later between the ages of 2 and 4 years old.
In some cases, perhaps if your little one is feeling extra vulnerable or stressed, they may even suck their thumb on occasion until they're about 8 years old.

When Should You Try to Help Your Child Stop Thumb-Sucking?

Although thumb-sucking is normal for young children, if it goes on beyond the age of about 5, it can become a concern. This is because once the permanent teeth start coming in, thumb-sucking can affect the shape of the mouth and affect how the teeth line up.
Once your child is about 4 or 5 years old, it may be time to wean them off this habit.
If your little one is a baby or toddler and you're concerned about thumb-sucking affecting their mouth, gums, or baby teeth, consult with their healthcare provider or dentist for personalized advice.

How to Stop Your Baby’s or Child’s Thumb-Sucking

For a baby, you don’t need to! It’s perfectly OK for your baby to be sucking their thumb. Once your child is nearing 5 years old or is any older and still thumb-sucking, you can work with them to help change the behavior.
Keep in mind, it won’t happen overnight, and you’ll need to be patient with your little one.
Begin the process when your child is feeling content and relaxed. Emotional stress can make them cling to thumb-sucking for comfort, making it harder to stop. Address any stressors in their life before focusing on breaking the thumb-sucking habit. For instance, if you're moving or expecting a new baby, consider waiting until things settle down.
Here are a few things you can do to help your child stop thumb-sucking:
  • Offer regular, gentle reminders. Your little one may not realize that they are sucking their thumb, so remind them calmly that they are doing it and that it’s not good for them. Be kind and reassuring and avoid scolding or criticizing them.
  • Understand the triggers. Is your child feeling stressed and turning to thumb-sucking as a comfort? Do they get nervous when you head off to work or drop them at preschool? Is there a certain time or place when this happens? If you're unsure what's causing their stress, have a chat with them and try to avoid those triggers. If your child seeks comfort before going to bed by sucking their thumb, you can take a few measures to help them get a better night’s sleep, such as giving them a bath before bed or reading them a bedtime story.
  • Use positive reinforcement. Try setting simple goals to motivate them, like avoiding thumb-sucking an hour before bedtime, then after dinner, and eventually throughout the whole day. Cheer them on with praise or a little treat every time they manage to go the whole period without thumb-sucking.
  • Consider aversive measures as a last resort. If your child is still sucking their thumb after trying these tips, it's a good idea to check in with their healthcare provider. They might suggest using a bitter-tasting nail polish or a thumb guard to help break the habit.
  • Talk to your child’s dentist. If your little one can’t break the habit, your child’s dentist can provide a personalized recommendation on what to do to protect your child’s teeth and mouth.

FREQUENTLY ASKED QUESTIONS

Thumb-sucking offers comfort and can be soothing for your baby, but there are no specific health benefits. In children under 5 years old, it’s generally harmless, but it can cause problems for the mouth and permanent teeth in older children.

The Bottom Line

No need to stress about thumb-sucking in babies. It's just a common way for them to find comfort. Most kids naturally give it up by age 4, if not sooner.
If your little one is still occasionally sucking their thumb after turning 5, it's usually not a big deal for their teeth or mouth. But if it's a regular habit by age 5, you can try some easy tricks to help them quit. Gentle reminders, praising them for going without thumb-sucking, and reducing stress can really help.
Patience and consistency on your part, and help from your child’s healthcare provider or dentist if it’s needed, will help your little one conquer the thumb-sucking habit once and for all.
While you’re here, you may also be interested in reading our guide on dental care for children, including how to brush your little one’s teeth, what to do about common teeth injuries, and more.


The information in this article is based on the expert advice found in trusted medical and government sources, such as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists. You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.

Related Articles

See more articles