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 central nervous system is the information highway of your body. Sleep is necessary to keep it functioning properly. During sleep, the brain rests busy neurons and forms new pathways so youâre ready to face the world in the morning. In children and young adults, the brain releases growth hormones during sleep. While youâre sleeping, your body is also producing proteins that help cells repair damage.