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.
âYou can never quite make it up,â she says. Adults aged 18 to 64 need to sleep for seven to nine hours a night, but some cope on six. For people over the age of 65, the recommended amount is between seven and eight hours, although some survive on five hours sleep (often waking up earlier and napping during the day).