In most cases Ringworm isn't that serious but if left untreated the Fungal Infection Ringworm can spread to other parts of the body making it more uncomfortable and harder to get rid of.
When you have Ringworm treat it as soon as possible to avoid it spreading.
Ringworm though is just a fungal infection and is not caused by any worms in your body so it's not that serious but it still needs to be treated before it spreads further.