This is an English rendering of a Polish public-health reference. The care paths it names (112, night and holiday care NiŚOZ, primary care POZ) are Polish. This is not medical advice.

PL

This is not medical advice Life-threatening emergency (Poland): 112

Home › Emotions and toddler defiance

When does the terrible twos phase start?

Applies to age: 18–30 months

In short

Tantrums usually start at around 18 months of age and are very common in young children; by age 4 they are much less common.

Sources: NHS, Portal PacjentaChecked: Approved: October 12, 2026Report an error

What is normal

All claims: international norm

  • Tantrums usually start at around 18 months of age and are very common in young children.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Temper tantrums usually start at around 18 months and are very common in toddlers.

    NHS · open the source · accessed: 2026-10-09 · license [1]

  • One reason is that young children want to express themselves, but find it difficult.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    One reason for this is toddlers want to express themselves, but find it difficult.

    NHS · open the source · accessed: 2026-10-09 · license [1]

  • By age 4, tantrums are much less common.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    By the age of 4, tantrums are far less common.

    NHS · open the source · accessed: 2026-10-09 · license [1]

  • Hitting and biting are also common in young children.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    Hitting and biting are common, too.

    NHS · open the source · accessed: 2026-10-09 · license [1]

When to worry

All claims: international norm

Worth discussing with a doctor:

  • If a parent is seriously worried about a child's behavior, it is worth seeing a doctor.
    Source: NHS – show the original wording (EN)

    Summarized and translated by the editors, not an official translation. Verbatim quote from the source, in its original wording:

    If you're seriously concerned about your child's behaviour, talk to your health visitor or GP.

    NHS · open the source · accessed: 2026-10-09 · license [1]

See a doctor

  • It is worth discussing with a specialist what worried the parent, and using the advice of a midwife, nurse or pediatrician.
    Source: Portal Pacjenta – show the quote

    Verbatim quote from the source:

    Polish original

    Warto jednak skonsultować ze specjalistą to, co Cię zaniepokoiło i korzystać z rad położnej, pielęgniarki czy pediatry.

    Portal Pacjenta · open the source · accessed: 2026-10-09 · license [2]

international norm “International norm” next to a section heading means its claims come from a non-Polish source, because no Polish source in our registry covers this topic. When this applies to only some of the claims, the foreign ones carry the same label next to their source.

International norm

“International norm” next to a section heading means its claims come from a non-Polish source, because no Polish source in our registry covers this topic. When this applies to only some of the claims, the foreign ones carry the same label next to their source.

Sources

  1. NHS (nhs.uk, Anglia)
    License: Open Government Licence v3.0. Source: NHS (nhs.uk, Anglia). Content summarized and translated by the editors; changed relative to the original. Contains public sector information licensed under the Open Government Licence v3.0. The summary is ours and is not attributed to the NHS.
  2. Portal Pacjenta (pacjent.gov.pl)
    License: CC BY 3.0 PL. Source: Portal Pacjenta (pacjent.gov.pl). Content summarized and translated by the editors; changed relative to the original.

See an error or outdated information? Report an error in this answer. Answer checked against the sources on October 20, 2026.

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