# illness

/ˈɪɫnəs/ (US) · /ˈɪlnəs/ (UK)

Source: https://englishreference.com/word/illness
Updated: 2026-06-19

## Senses

### 1. a specific disease

noun · CEFR A2

a specific disease or period of being sick.

For teachers: a specific instance of disease or a period of sickness. Countable in this sense.

- She missed two weeks of school because of a sudden illness.
- The doctor struggled to diagnose the mysterious illness that had affected several passengers during the long flight.

Usage: Often used with adjectives like 'serious', 'minor', or 'chronic'.

### 2. the state of being sick

noun · CEFR B1

the general state of being unwell or having poor health.

For teachers: the general condition of being unhealthy or diseased. Uncountable in this abstract sense.

- The company provides insurance to help workers during times of illness.
- Public health initiatives aim to reduce the burden of illness in urban populations through better sanitation and vaccination programmes.

Usage: Often used in formal contexts regarding public health or statistics.

## Examples

- She missed two days of work because of a sudden illness.
- The doctor asked several questions to determine if the patient's illness was caused by a virus or bacteria.
- Chronic illness often requires a multifaceted approach to management, balancing medical intervention with lifestyle adjustments to maintain a reasonable quality of life.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.