By Mindy from her Purposefully Simple Blog:

I’m not a doctor or lactation consultant. I’m a mom who has dealt with the difficult nursing and slow baby weight gain that a tongue or lip tie can cause and wanted to pass on what I know in the hope that it can help another mom get the help she and baby need to continue breastfeeding.

Some of the symptoms and signs are not specific to tongue or lip ties. Individually each symptom could point to any number of causes but having more than one or a handful of these signs and symptoms is an indication that your problem might be tongue or lip tie (or both as in our case).

Signs of a tongue tie

Baby:

  • Can’t stick out tongue
  • has a lip tie (a lip tie usually means there is a tongue tie but not necessarily in the reverse)
  • has slow weight gain or failure to thrive
  • is unable to latch, stay latched or slips off the nipple
  • has prolonged feedings and is unsatisfied afterwards
  • has short frequent feedings and is unsatisfied afterwards
  • pops or clicks during nursing
  • is unable to hold pacifier or bottle nipple in mouth
  • gums the nipple

Mom:

  • has cracked, bleeding, or sore nipples and/or pain while nursing
  • has flattened or blanched nipples
  • suffers from plugged ducts, mastitis, or thrush

Signs of a lip tie

  • Lip doesn’t flare out when latching
  • Colic, Gas or reflux (a bad latch lets in air which causes these symptoms but they can be caused by other things such as dairy or other food sensitivity)
  • Unable to open mouth wide enough to latch

What to do if you suspect a tongue or lip tie

  • Trust your instincts! You know yourself and your baby best. You might be unsure of whether your problem is a tongue and/or lip tie or something else but you probably know there is a problem.
  • Consult an International Board Certified Lactation Consultant (IBCLC) or pediatrician who is knowledgeable and supportive of breastfeeding. Keep getting opinions until someone can help you.

Benefits of tongue and lip tie revision

    • Better latch means easier and pain-free nursing. Mom and baby can enjoy nursing and baby can thrive receiving the very best food and the wonderful bonding experience nursing provides.
    • Unrevised tongue or lip tie has been known to cause the following problems later in life:
      • Speech problems – delayed development, deterioration, life long speech difficulty
      • Tired, painful jaw
      • Space between teeth (lip tie)
      • Trouble chewing and eating age appropriate foods
      • Migraines
      • Dental health problems

SOURCE: http://www.purposefullysimple.com/does-your-baby-have-a-tongue-or-lip-tie/