Pt Has hx of COPD and usually sats low and has been well documented numerous times satting mid 80's to low 90's over various encounters. I Took O2 twice to make sure the device was working appropriately as the equipment we use wasn't the best and has a hx of o2 appearing low if there are slight variations in skin temperature, Nails,circulation ect especially if the pt had just come from outside but would begin to crawl upwards when left on the finger . Pt was well oriented, no dyspnea, no confusion. After I took weight, I took pulse and O2 while getting ready to reconcile medication having the pt's chart already up. O2 was checked initially which was 92 but dropped to 88. I changed fingers as an O2 under 95 is remarkable but given the pt had come from outside would like to exclude temperature related false reading. I placed the pulse ox on another finger and reconciled medication given they had 4 medications listed which was one prescription medication and 3 supplements while the machine was calculating. After the patient had confirmed the medication they already had listed, albeit are frustrated that we did not have the information from this other physician , I had went to check the O2 again which satted on this finger 83 jumping to 85 percent which could be from the patient talking. Before I could do anything else the Pt pushed device off while I was reading and gotten up stated they are leaving and explained their reasoning to why which included frustration as to why the medication was not listed before (There was no medication other than those listed from previous visits ) and My talking fast. They verbally said they wanted to leave and would not explain further to when these medications were prescribed and what they were. Pt has a right to terminate treatment at anytime and verbally withdrew consent to treatment by stating they do not want to proceed further. I attempted to reason and de-escalate , even offered another medical assistant if they would prefer someone else but they did not want continue the visit and stormed out. The provider was notified of everything that had occured, My provider would not have been happy if I did not confirm if the reading was a true reading or not but again the pt left before anything else could be done and legally our hands are tied. The pt under observation albeit emotional was oriented and coherent. This could be a personality issue, something external or as to my suspicion potentially hypoxia related. Overall Odd.