Hi. That's a great questions. It is hard to say for certain, but, what you have described seems to be the case of spider mites. In Ontario and other cooler climates, during the winter months our indoor environment tends to become dry. This is usually a result of running our furnaces and not having a humidifier in most homes.
With low humidity and cooler temperatures, this is very inviting for spider mites for most indoor house plants. The spider mites are usually very small (almost invisible) white specs. They actually eat away at the plants outer cells and breed like crazy on the bottom of the leaves.
The best way to combat spider mites is by increasing the humidity around your plant and also using an spider mite soap. This can be found at most hardware centers. You can also make your own insecticide spray by mixing water and palm olive soap in a spray bottle. Every two days give your plant a good spray and you will see a great improvement.
For more info check out our blog post on spider mites! https://greenhousetogarden.ca/how-to-kill-remove-spider-mites-on-your-plants/