illness
- disease
‘illness’
If you have an illness, there is something wrong with your health. An illness can last for a long time or a short time, and its effects can be serious or not serious.
The doctor thought that Bae's illness was caused by stress.
You can use the adjectives long and short in front of illness, but not in front of disease.
He died last month after a long illness.
‘disease’
A disease is a particular kind of illness caused by bacteria or an infection. Diseases can often be passed from one person to another.
Glaucoma is an eye disease.
Children should be immunised against dangerous diseases.
Animals and plants can also have diseases, but not illnesses.
Scrapie is a disease that affects sheep.
The trees were killed by Dutch Elm disease.