Insomnia can be a symptom of a disease or a side effect of medication. It's not itself a disease.
Rover
Is the following wording is acceptable?
Insomnia is asymptom of the disease, just like a fever or a stomachache. It’s not a disease in itself.
Insomnia can be a symptom of a disease or a side effect of medication. It's not itself a disease.
Rover