MedlinePlus is a service of the National Library of Medicine (NLM), the world's largest medical library, which is part of the National Institutes of Health (NIH). It was built as an online health information resource for patients and their families and friends.
MedlinePlus presents high-quality, easy to understand, relevant health and wellness information that is trusted.
MedlinePlus at a Glance
- Offers information on health topics, human genetics, medical tests, medications, dietary supplements, and healthy recipes.
- Sourced from more than 1,600 selected organizations.
- Provides 40,000 links to authoritative health information in English and 18,000 links to information in Spanish.
- In 2018, 277 million users viewed MedlinePlus more than 700 million times.
Teen Development
As a teenager, you go through many physical, mental, emotional, and social changes. The biggest change is puberty, the process of becoming sexually mature. It usually happens between ages 10 and 14 for girls and ages 12 and 16 for boys. As your body changes, you may have questions about sexual health.
During this time, you start to develop your own unique personality and opinions. Some changes that you might notice include:
- Increased independence from your parents
- More concerns about body image and clothes
- More influence from peers
- Greater ability to sense right and wrong
All of these changes can sometimes seem overwhelming. Some sadness or moodiness can be normal. But feeling very sad, hopeless, or worthless could be warning signs of a mental health problem. If you need help, talk to your parents, school counselor, or health care provider.
Centers for Disease Control and Prevention
