Sickness vs Diseases - What's the difference?

As nouns the difference between sickness and diseases

is that sickness is the quality or state of being sick or diseased; illness; disease or malady while diseases is plural of lang=en.

(en-noun)

The quality or state of being sick or diseased; illness; disease or malady.

I do lament the sickness of the king. -

Trust not too much your now resistless charms; Those, age or sickness soon or late disarms. -.

Sickness is a dangerous indulgence at my time of life. -.

Nausea; qualmishness; as, sickness of stomach.

* nausea * disease * illness * infirmity * malady

* car sickness * homesickness * motion sickness

(head)