Adolescence is a crucial developmental stage that has long-term effects on a person's health and well-being as well as the welfare of society at large. Children learn how to understand abstract concepts, form moral beliefs, and create and sustain fulfilling relationships during adolescence. During adolescence, young people go through a variety of transformations as they become physically adults. Changes in the youth begin with the appearance of secondary sexual traits. Dynamic brain development that is distinguished by interaction with social circumstances throughout adolescence impacts the talents that a person carries into adulthood. In girls, there is the onset of the menstrual cycle, which leaves a big impact on their body. Adolescents across the globe have a lifestyle risk index comprising risky drug and alcohol consumption, unprotected sex, sleep duration, and smoking, which is a fair to good indicator of medical conditions connected to lethal (performing suicide and self-harm) and non-fatal (major depressive disorders and severe psychological distress) diseases. According to the findings of this study, the lifestyle risk index is a valuable summary indicator in the context of teenage health promotion and noncommunicable disease prevention. Adolescent lifestyle risk variables were discovered to cluster, giving additional backing for the deployment of numerous health behavior modification interventions rather than those having a single behavior emphasis. 

The development of the neurobiological mechanisms underlying higher cognitive capabilities and social and emotional behavior occurs most rapidly during adolescence. However, emotions are intricate phenomena made up of several subprocesses. In this article, we make the case that looking at emotional and cognitive development from a process-level approach enables crucial insights into the mechanisms underlying teenagers' fluctuating moods and increased risk of psychosocial changes. Adolescence is also a time when emotional capacity changes, including enhancements in affective modulation and emotional cue discrimination. According to functional imaging studies utilizing cognitive and affective difficulties, frontal cortical networks go through developmental changes in processing. The complex paths that intersect in a unique way during adolescence are revealed by comparing the developmental progressions for the physiological sensitivity to emotion, emotional regulation ability, and motivation to experience particular affective states. We analyze how these overlapping trajectories may affect both positive outcomes, such as adolescent social relationships, and negative consequences, including psychosocial behavioral changes.

On the mainstream media, a platform that constantly evolves, youngsters may communicate with one another, express themselves, and share material of all types. It has led to the establishment of a brand-new cultural framework that affects how people interact as well as how organizations and technologies are used. Hypothetically, mass media is considered an instrument with two sharp blades. Although it provides benefits, children may experience some drawbacks as well. Even though mass media is typically discussed negatively, there are some compelling arguments in its favor. Juveniles and adolescents have the capacity to be knowledgeable viewers of media. They do not just take in everything they see, read, or hear on social networks or in the headlines. You can help kids develop the skills necessary to control media effects. Teenagers and young people are vulnerable to intentional and direct media influence. The news media might potentially indirectly affect anything. In a nutshell, youth are significantly impacted by the media. It may influence how they think and act, which may cause severe social difficulties. This matter should be managed by adults. 

In order to stay healthy, you need to eat a variety of nutritious food every day. Teenagers go through big physical changes in puberty. They need extra nutrition to cater to these changes. The level of physical activity and stage of development will determine exactly how much healthy food one needs. Nutrition is the study of food in relation to the health of an individual, community or society and the process through which food is used to sustain life and growth. Good nutrition means eating the right amount of healthy food and not skipping meals. Essential nutrients are compounds that the body cannot make or have in insufficient amounts. According to the World Health Organization, these nutrients must come in food and are vital for disease prevention and good health. These essential nutrients are calcium, iron, protein, zinc and micronutrients like vitamin D, vitamin E, potassium and fiber. Adolescents tend to eat more meals away from home. Eating the wrong types of food after long intervals and unhealthy eating can cause nutritional deficiency in adolescence. Adolescence needs extra nutrients for optimal physical growth, bone growth and strength, pubertal growth and development, hormonal changes, organ and tissue development, including the brain, increased physical activity levels and basal metabolic rate. Adolescence is a growing phase of life, and having a balanced food is very important. Adolescents should not skip their breakfast; they should drink plenty of water and limit highly processed food, sugary drinks and eating out. Healthy eating habits and physical activity help lower the risk of obesity during adolescence. Any nutritional deficiency experienced during this critical time of life can have an effect on the future health of the individual. All parents should pay attention to the nutritional needs of their teenagers. Adolescence, the period between childhood and adulthood, is a window of opportunity for improving nutritional status and correcting nutritional practices.

Bulimia nervosa (BN) is a serious mental illness that frequently shows symptoms in adolescence or early adulthood. Binge eating and incorrect compensatory behavior to regulate weight are hallmarks of the eating disorder bulimia nervosa, which can have potentially harmful consequences. Although the exact cause of bulimia nervosa is unknown, it is most likely complex. The binge-like conduct linked to this illness may be influenced by the anomalies in interoceptive function, notably of the insula. Although the exact origin is unknown, scientists think a combination of genetic, biochemical, psychological, social, and behavioral variables is to blame. Treatment for bulimia will be more successful the sooner it is discovered. Treatments that work concentrate on nutrition, self-worth, problem-solving, coping mechanisms, and mental wellness. These therapies assist patients in the long-term maintenance of good behaviors.

Adolescence is a vital developmental stage in which personal lifestyle choices and behavior patterns emerge, including the decision to be physically active. Physical inactivity, lazy behavior, and low oxygen consumption are all substantial risk factors for the development of chronic illnesses, which result in morbidity and death, as well as an expensive burden on society from health and social care services and decreased occupational productivity. During adolescence, a unique mix of biological and psychological elements combine to generate a special necessity for health-related physical exercise. At the same time, many of these variables operate as impediments to encouraging youngsters to develop regular exercise routines. Teenagers and young adults are becoming more aware of its importance, especially in light of our culture's constant connectedness and media consumption. This chapter focuses on physical inactivity among teenagers, the risks they promote and the different ways to cure such problems.

Sleep plays a critical role in sustaining health and well-being in teenagers and young adults, and this link is increasingly studied. Many young patients who visit doctors have problems or diseases that are related to sleep deprivation. Due to the accelerated brain development that occurs throughout adolescence, sleep may be especially crucial during this time. Pre-adolescents and teenagers have different average sleep durations, but for both age groups, 9 hours seems to be the ideal amount of sleep. However, evidence indicates that teenagers frequently do not get enough sleep, particularly during the week when school is in session. Sleep has a variety of purposes, such as fostering cognitive, physical, and immune development. Studies have also shown a link between insufficient sleep and adult cardiac disease. Teenagers and young adults are becoming more aware of its importance, especially in light of our culture's constant connectedness and media consumption. This chapter focuses on the irregular sleeping patterns among teenagers, the risks they promote and the different ways to cure such problems.

In today's world, epidemic levels of kid obesity may be seen in both industrialized nations and poor countries. It is common knowledge that excessive weight gain and obesity in children have a detrimental effect on physical health as well as mental health. Children who are overweight at a younger age are at a greater risk of emerging non-communicable illnesses, such as cardiovascular and diabetes conditions, including a greater possibility that they remain overweight when they reach adulthood. It is believed that obesity is a disorder that may be caused by various different reasons; however, the process of obesity is not completely understood. The increasing prevalence of obesity around the globe may be attributed in large part to environmental factors, the decisions that people make about their lifestyles and the cultural contexts in which they live. It is generally believed that an increase in the amount of calories and fat that one consumes is the main reason for obesity and overweight. Alternatively, several facts show that factors influencing the worldwide increase in obesity rates include extreme sugar intake in soft drinks and a continual reduction in physical movement. Children’s obesity may have detrimental effects on a child's physical health, along with their emotional and social health, as well as their sense of self-worth. There is a connection between this and a child's poor scholastic progress as well as their worse quality of life. In addition to juvenile obesity, a number of co-morbid diseases are also prevalent in children. These co-morbid illnesses include hepatic, metabolic, orthopedic, pulmonary, neurological, renal, and cardiovascular disorders. Other co-morbid illnesses include diabetes and asthma.

Adolescence is a crucial period of biological, psychological, and social development; hence, it is at higher risk of drug use and its negative effects. Adolescence is a crucial developmental stage that involves important behavioral, emotional, social, and cognitive changes. Teenagers may be predisposed to begin drug use, develop substance use disorders, and experience potentially substantial and permanent substance-related negative outcomes due to the neurobiological changes underpinning these intricate developmental processes. This chapter includes the study of recent research on this complicated subject, which aims to guide clinical care and research on teenagers. This chapter is about how addiction to drugs and substances of abuse is spreading among the youth and has become a serious problem. The chapter includes all the harmful effects of this practice among youth and how this habit is disturbing the young minds of our country with its bad impact on the thinking and decision-making power of youth, especially in the people taking drugs regularly. Types of substances of abuse and drugs, along with the ways by which they are taken by individuals, are also discussed in this chapter. Diseases associated with it and the neurological disturbance created by such drugs in individuals who are habitual of taking them are also reviewed and mentioned in this chapter in detail. Further, this chapter includes the law and order followed in our country regarding drugs and substances of abuse. Since addiction to the substance is a major problem, it is very important to get rid of this habit; for this, some ways are being used. Adolescent substance use is diverse, ranging from pathological to normal, and it can cause severe short- and long-term illnesses and even mortality. Adolescent drug use issues must be addressed by comprehending risk and resilience factors, underlying neurobiology, and the best developmentally sensitive therapies.

Adolescence is a period in the life of an individual from 10 years to 19 years of age. This stage is marked by rapid physical, cognitive, and psychosocial growth in an individual and is a very crucial stage for their development. This is the time when the foundations of a healthy or unhealthy lifestyle are laid, and these habits may continue for a lifetime. Current research studies show high growth in the number of adolescents involved in risky behaviors, and this has become a matter of concern. The prevalence of risks in alcohol and tobacco consumption has increased tremendously. Tobacco and alcohol are known to be ‘gateway drugs’ as they are the first to be consumed when an individual starts such practices; the reasons are their easy availability, peer influences, acculturation, or even family history of substance use disorder. To decrease this and establish a healthy lifestyle, teenagers need proper information and guidance, including opportunities that may lead them to actively participate in interventions that are aimed to improve their physical and mental health. Mostly, alcohol and tobacco are seen to be prevalent together. Adolescents who show consistent drinking and tobacco smoking habits are more likely to show irritant, violent behaviors. Also, they are at higher risk of developing drug habits like marijuana abuse in their later stages of life.

This chapter basically examines the generality of tobacco and alcohol consumption, especially among adolescents, and the ways in which it causes harm to adolescents and its side effects. It gives an overview of the social, physical, and psychological effects it has on adolescents’ lifestyles. It also covers risk factors and smoking and alcohol cessation efforts in the population. It gives special consideration to smoking cessation treatment, which includes peer influences, motivation, and nicotine dependence.

Adolescence, a transitional phase from childhood to adulthood, is marked by several critical changes in the human body, whether emotional, physical, psychological, or social. This sensitive phase, which primarily lasts from 10-19 years of age, lays the trajectory for overall development and health among adults. Neurobiological, environmental, genetic aspects, lifestyle, and behavioral factors, such as eating disorders, substance abuse, social media, physical inactivity, sex-related differences, etc., can lead to disease onset, with anxiety and depression being the prominent ones. Besides, the adolescent brain is structurally different from the adult brain, with varying levels of hormones and neurotransmitters, making it more vulnerable to changes. Prevention, prompt diagnosis, and treatment are vital to improving adolescent mental health. Preventive interventions and mental well-being awareness are paramount to alleviating health loss. This chapter will mainly focus on the molecular basis of the adolescent brain, causes and symptoms of anxiety and depression, neuropsychiatric overview, appropriate measures for prevention, timely diagnosis, intervention, and treatment, and the role of society in shaping the adolescent brain.

Adolescents and children have been deemed more vulnerable to the impacts of air pollution than adults. Every day, almost 93% of the world's children and adolescents breathe dirty air, putting their health and development in danger. It demonstrates that pregnant women exposed to polluted air are more likely to give birth prematurely and have small, low-birth-weight babies. Air pollution has an impact on neurodevelopment and cognitive aptitude, as well as the risk of developing asthma and pediatric cancer. Children who have been exposed to high levels of air pollution may have a higher chance of developing chronic diseases such as cardiovascular disease later in life. One reason children are especially exposed to the impacts of air pollution is that they breathe faster than adults and thus absorb more toxins. They also reside closer to the ground, where some contaminants reach peak concentrations, during a period when their brains and bodies are still growing.

Numerous studies have revealed that air pollution has a negative impact on adolescents' health, with a particular emphasis on physical disorders, such as respiratory ailments. Furthermore, a few studies have found that kids who are exposed to poor air quality suffer from increased fatigue and mental issues both during and after the exposure.

Air pollution is a global health concern that has major public health consequences, especially for youth. In addition to short-term impacts, early exposure to criterion air pollutants may be related to low birth weight, increased oxidative stress, and endothelial dysfunction, all of which may have long-term consequences for chronic noncommunicable diseases. Given the emerging epidemic of chronic disease in lowand middle-income countries, as well as the vicious cycle of rapid urbanization and rising levels of air pollution, public health, and regulatory policies to protect air quality should be integrated into the primary healthcare system's main priorities and health professionals' educational curricula.