Ill or Sick?

by Craig Shrives

What Is the Difference between "Ill" and "Sick"?

"Ill" and "sick" are easy to confuse because they both describe poor health. However, there is a difference between "ill" and "sick."

The adjectives "ill" and "sick" both mean "unwell." With the exception of their use in set terms (e.g., sick leave, ill health), "ill" and "sick" can usually be used interchangeably, but "sick" dominates in both the UK and the US.

In British English, "ill" is used a little more commonly than in the US (especially with the verb "to feel").

In both American and British English, "sick" is the preferred word when someone is physically vomiting or feeling unwell temporarily.

The following graph shows how "sick" dominates over "ill" in UK and the US:
sick or ill

More about "Ill" and "Sick"

"Sick" is commonly seem in these terms:
  • sick day
  • sick leave
  • sick pay
  • seasick
  • carsick
  • sick and tired
"Ill" is commonly seen in these terms:
  • terminally ill
  • ill-health
  • to take ill

Example Sentences with "Sick" and "Ill"

Here are some examples featuring "sick" and "ill":
  • I can't travel by boat because I feel sick immediately. correct tick
    • (Here, "sick" refers to physically vomiting. In this context, "sick" is preferred over "ill.")
  • Being healthy is the crown that only the sick can see. A lot of times, we take it for granted. correct tick (Comedian Hasan Minhaj)
    • (Here, "sick" refers to being in poor health. Even in this context, "sick" is more common than "ill.")
  • Kate has taken ill with a chest infection. correct tick
    • ("To take ill" is a set phrase.)
  • The most important thing when ill is to never lose heart. correct tick (Premier of the Soviet Union Vladimir Lenin)
    • (This was a translation by a British interpreter. An American interpreter would likely have used "sick," but both words are an option.)

Illness, Sickness, or Disease?

Although "sick" and "ill" can be used interchangeably, "sickness" and "illness" cannot. Medical sociology has long made the distinction between illness and sickness.
  • A sickness is the society's or community's view of an illness or other condition (not necessarily a medical condition).
  • An illness is a period of sickness affecting the body or mind.
  • A disease is a medical condition. Only a medical professional can diagnose a disease.

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See Also

adverse or averse? affect or effect? appraise or apprise? avenge or revenge? bare or bear? complement or compliment? dependant or dependent? discreet or discrete? disinterested or uninterested? e.g. or i.e.? envy or jealousy? imply or infer? its or it's? material or materiel? poisonous or venomous? practice or practise? principal or principle? bear or bare with me? who's or whose? What are adjectives? List of easily confused words