When someone stops using tobacco and nicotine products, it can take more than two weeks for the blood level of cotinine to drop to the level that a non-tobacco user would have and several weeks more for the urine level to decrease to a very low concentration.
Pre-school children require 10-13 hours a day. School-age children require 9-11 hours a day. Teenagers need about 8.5-9.5 hours on average. Most adults need 7 to 9 hours a night for the best amount of sleep, although some people may need as few as 6 hours or as many as 10 hours of sleep each day. Women in the first 3 months of pregnancy often need several more hours of sleep than usual.
Your age has a lot to do with sleep requirements. Babies need about 16 hours a day and teenagers about nine. Most adults need seven to eight hours a night, but some may need as little as five hours or as much as 10 hours of sleep a day. Generally speaking, the older you get, the less sleep you need.