My father had a painful limp before he died, according to his next door neighbor. We know from the autopsy that he had developed phlebitis and he made and kept an appointment with his doctor, who apparently wasn't paying attention to why Dad went to see him. Instead of hospitalizing him and putting him on blood thinners he scheduled the heart tests a week later. (Dad got those regularly.)
Dad died of a pulmonary embolism from the phlebitis before he could keep either of those appointments. If the doctor (who I stopped seeing years earlier because of a misdiagnosis and I cautioned Dad about continuing to see him) had caught it Dad might still be around. He'd be in his mid-80s.