Why Do Babies Lose Their Hair?

The first weeks and months of a baby’s life are full of big changes. But what new parents may not have expected are the tiny hairs left on their newborn’s mattress. After a few months, their baby’s once-full head of hair has become thin and patchy — or nearly bald.  Fortunately, infant hair loss is rarely a concern. A fetus starts growing hair during the first trimester. But whether an infant is born with a layer of fuzz or a thick mop, all lose at least some hair. In fact, hair loss simply means an infant is making the huge adjustment to life outside the womb.

Why Do Babies Lose Their Hair?

On an adult’s head, each strand of hair goes through a phase when it’s growing and when it’s not — and when hair isn’t growing, it can also shed. At any given time, only a small percentage of your hair is in this latter stage, and only about 50 to 100 strands are lost per day. Not so for a newborn.

There are other conditions that cause hair loss, but they’re very uncommon in children under 12 months old:

  • Patchy bald spots with red, flaky scaling (and sometimes black dots where the hair has broken off) may mean that your baby has a contagious fungal infection called tinea capitis.
  • Physical damage – from tight ponytails, for example – can result in hair loss called traction alopecia.
  • Irregular patches of hair may fall out if your older baby twirls or pulls his hair compulsively. This is called trichotillomania.
  • If your baby has smooth, round, totally bald areas, he may have alopecia areata, a condition in which the immune system attacks the hair follicles, drastically slowing hair growth. This type of hair loss usually appears in isolated patches, although it can affect all of the hair on the body.
  • Some medical conditions – such as hypothyroidism (a thyroid disorder) or hypopituitarism (an underactive pituitary gland) – can cause hair loss all over your child’s head.