Hello, Yes, regular smoking habits do cause changes in the blood and urine. Nicotine and Cotinine can be detected in the pathological tests. The by-product Cotinine can stay in the hair follicles for about three months after quitting smoking. Get bald to stay on the safer side. To detox take plenty of water, juice and soups to flush it out of your system. Take antioxidants like oranges, kiwi, carrot, broccoli, spinach, etc. Take balanced home made food. Do exercises to boost better blood circulation, sweats help to flush out nitrogenous waste products. After three to four days of quitting smoking and performing detox, the blood and urine should show clear reports. Anyways, work hard. Since you are not obese and have good metabolism, it should work. Smoking is a bad addiction, come out of it to avoid health hazards & complications later in life. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician