i just extended my visit visa but under husband's sponsorship.i went to medical commission (near industrial area) for xray and blood extraction. result of medical will be sent to you via sms, and return to that same building for verification (please bring the receipt and paper they have given you for stamping).Proceed to Qatar's Immigration Dept,have your data typewritten or translated in arabic (they have separate bldg. but within immigration area too).If i am right, visa extension application is on Bldg.4,you need to get a number and wait for your turn to be called.extension is QAR 200/month. if it happens you have expired visa, you will spend more than that PER Day as penalty.Renew your visa before it expires.hope this could help.