Occurring or progressing with few or unnoticeable symptoms, so that the individual is unaware of the onset of the disease.
Refers to the onset of a disease without symptoms.
Causing harm without showing any obvious signs.
To gradual, subtle, or hard-to-discern development, as in a disease (e.g., glaucoma) that develops without early symptoms.
Of gradual, subtle, or indistinct onset; said of some slowly developing diseases.
Advancing steadily and subtly, yet carrying significant consequences, is a characteristic of a condition that progresses insidiously.
The secretive and inconspicuous advance of an illness or disorder.