H.L is a 46-year-old man who is relatively healthy but obese. Weight: 250 lbs. Height: 5 ft 9 in. He comes to the clinic to see the nurse practitioner with the following statement: "I must have pulled something in my right leg. I was walking when I felt some soreness in my lower right leg, and now there is pain and swelling." H.L reports sitting for hours at a computer with few breaks. He occasionally remembers to exercise his feet and lower legs. The right calf pain and swelling began 3 days ago. H.L reports discomfort in his right lower leg, especially when he is up and moving around. He states that he has taken acetaminophen 1,000 mg 2-3 times per day to relieve leg pain. He has hypertension and hyperlipidemia, both controlled by medication. He has had no angina since his coronary artery bypass graft (CABG) 5 years ago. He developed a pulmonary embolism following surgery. He has no other previous surgeries on veins or arteries. H.L is a nonsmoker, drinks occasionally, and exercises by walking a few blocks most days. He denies problems with sexual activity.