What can cause a drastic increase of cholesterol levels lin a short period?

A few things: Five major players come to mind with a rapid spike in cholesterol. Significant dietary changes, a change in your genetic phenotype (when bad genes catch up to you), certain medications/supplements, hormonal shifts, or lab error. Typically with an unexpected change in lab values it is worthwhile repeating the test or performing a more specific lab test prior to considering how to move forward.