If exercise feels harder than it should, chronic stress may be working against you. Learn how to regulate your physiology so ...

Muscle twitches fall into two main types. There’s myoclonus, where a whole muscle or group of muscles twitch or spasm. Then ...

Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't ...

Medically reviewed by Michael Menna, DO Key Takeaways The circulatory system carries oxygen and nutrients throughout the body and removes waste.The lymphatic system helps fight disease by creating and ...

Skeletal muscle is the type of muscle that controls movement. Problems with these muscles can be minor, life-threatening, or ongoing problems that make it hard to perform basic daily activities.

Repeated exercise, or wasting, can change the way key genes work.