Ear wax is good for the health of your ears and it plays a vital role in preventing infection and removing debris from the ear canal. However, some people produce more than others, making them prone to a build up over time that can become hard and impacted, leading to irritation, hearing loss, or infection, if not removed.
Using ear plugs or earphones can encourage wax to build up and if you use cotton buds (never recommended), you could be pushing the wax further down the ear canal causing it to harden and become impacted, potentially leading to permanent damage.
Certain skin conditions, like eczema can also contribute to excess ear wax.