Health Library
![](https://cdn.statically.io/img/healthlibrary.brighamandwomens.org/wellnessCenter.png)
You may wonder what all the fuss is about exercise. Simply put, inactivity is hazardous to your health. Physical activity can help you prevent chronic disease, manage your weight, and stay mentally fit. The best news is that it's never too late to adopt a more active lifestyle.
Pregnancy is an exciting time for parents-to-be. You want to know as much as you can about your developing baby and how your actions will affect his health. Use this information to help you make informed decisions from conception through delivery.
Enjoy good health at every age: know your body and how it works, eat well and stay active, and follow a plan for disease prevention.
![](https://cdn.statically.io/img/healthlibrary.brighamandwomens.org/InteractiveTools-Quizzes.png)
Radon is a gas that you can't see or smell, but is present in nearly all the air around us. Everyone breathes in radon every day, usually at low levels. People who inhale high levels of radon are at increased risk for developing lung cancer. Radon is a problem in homes in which higher concentrations collect. Find out more about radon by taking this quiz.
Experts are increasingly urging people to know their BMI, a figure that takes into account not just weight but also height to indicate body fat.
Breast cancer is the most commonly diagnosed cancer in women (other than skin cancer). The American Cancer Society reports the breast cancer death rate is declining, probably because of earlier detection and improved treatment. This short assessment will help you determine if you have major risk factors for breast cancer.
![](https://cdn.statically.io/img/healthlibrary.brighamandwomens.org/clear.gif)
Myasthenia gravis is a disease of the central nervous system characterized by sporadic muscular fatigue and weakness. It occurs chiefly in the muscles of swallowing and chewing, as well as the muscles of the eyes, face, and neck. This video explores possible causes of this disease, as well as available treatments.