Hot compresses and eyelid hygiene can help reduce the swelling and pain of a stye. If it does not improve or get worse in a few days a complete ophthalmologic exam should be performed.

A stye can go away on its own. Try warm compresses twice a day for a week. If it is not gone by then see an ophthalmologist.

While it is possible to go away on its own it is unlikely. I would at the minimum recommend the use of warm compresses. A warm tea bag or face cloth for 30 seconds to a minute reheated as necessary as often as possible, no less than three times a day. Alternatively seek a ophthalmogist to prescribe a steroid ointment and or injection of medication into the sty, as a last resort there is incision and drainage of the sty

Small ones may recover spontaneously but may leave behind a small nodule permanently on your eyelid. It is best to see an ophthalmologist for advice..